diff --git a/src/adapter/memory_adapter.rs b/src/adapter/memory_adapter.rs
index e1e7fb63..7e97401b 100644
--- a/src/adapter/memory_adapter.rs
+++ b/src/adapter/memory_adapter.rs
@@ -1,18 +1,52 @@
 use crate::{
     adapter::{Adapter, Filter},
     model::Model,
+    util::parse_csv_line,
     Result,
 };
 
 use async_trait::async_trait;
 use hashlink::LinkedHashSet;
 
+use super::StringAdapter;
+
 #[derive(Default)]
 pub struct MemoryAdapter {
     policy: LinkedHashSet<Vec<String>>,
     is_filtered: bool,
 }
 
+impl From<StringAdapter> for MemoryAdapter {
+    fn from(string_adatpter: StringAdapter) -> Self {
+        let string_policies = string_adatpter.policy.split("\n");
+        let mut memory_adapter = Self {
+            policy: LinkedHashSet::new(),
+            is_filtered: false,
+        };
+        for line in string_policies {
+            if let Some(tokens) = parse_csv_line(line) {
+                let ptype = tokens[0].clone();
+                if let Some(sec) = ptype.chars().next().map(|x| x.to_string()) {
+                    let mut rule = tokens[1..].to_vec();
+                    rule.insert(0, ptype);
+                    rule.insert(0, sec);
+                    memory_adapter.policy.insert(rule);
+                }
+            }
+        }
+        memory_adapter
+    }
+}
+
+#[allow(clippy::should_implement_trait)]
+impl MemoryAdapter {
+    pub fn from_str(s: impl ToString) -> Self {
+        let s = s.to_string();
+        let string_adapter = StringAdapter::new(s);
+        Self::from(string_adapter)
+    }
+}
+
 #[async_trait]
 impl Adapter for MemoryAdapter {
     async fn load_policy(&mut self, m: &mut dyn Model) -> Result<()> {
@@ -232,3 +266,132 @@ impl Adapter for MemoryAdapter {
         self.is_filtered
     }
 }
+
+#[cfg(test)]
+mod test {
+    use hashlink::LinkedHashSet;
+    #[cfg(target_arch = "wasm32")]
+    use wasm_bindgen_test::*;
+
+    use crate::{
+        adapter::StringAdapter, Adapter, CoreApi, DefaultModel, Enforcer,
+        Filter, MemoryAdapter,
+    };
+
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-async-std"),
+        async_std::test
+    )]
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-tokio"),
+        tokio::test
+    )]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    async fn test_load_policy() {
+        let policy = "p, alice, data1, read\np, bob, data2, write";
+        let mut adapter = MemoryAdapter::from_str(policy);
+        let mut model = DefaultModel::from_str(include_str!(
+            "../../examples/rbac_model.conf"
+        ))
+        .await
+        .unwrap();
+
+        adapter.load_policy(&mut model).await.unwrap();
+        let enforcer = Enforcer::new(model, adapter).await.unwrap();
+
+        assert!(enforcer.enforce(("alice", "data1", "read")).unwrap());
+        assert!(enforcer.enforce(("bob", "data2", "write")).unwrap());
+        assert!(!enforcer.enforce(("alice", "data2", "read")).unwrap());
+    }
+
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-async-std"),
+        async_std::test
+    )]
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-tokio"),
+        tokio::test
+    )]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    async fn test_save_policy() {
+        let policy = "p, alice, data1, read\np, bob, data2, write";
+        let mut adapter = MemoryAdapter::from_str(policy);
+        let mut model = DefaultModel::from_str(include_str!(
+            "../../examples/rbac_model.conf"
+        ))
+        .await
+        .unwrap();
+
+        adapter.load_policy(&mut model).await.unwrap();
+        adapter.save_policy(&mut model).await.unwrap();
+
+        let mut expected = LinkedHashSet::new();
+        expected.insert(
+            vec!["p", "p", "alice", "data1", "read"]
+                .iter()
+                .map(|s| s.to_string())
+                .collect::<Vec<String>>(),
+        );
+        expected.insert(
+            vec!["p", "p", "bob", "data2", "write"]
+                .iter()
+                .map(|s| s.to_string())
+                .collect::<Vec<String>>(),
+        );
+
+        assert_eq!(adapter.policy, expected);
+    }
+
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-async-std"),
+        async_std::test
+    )]
+    #[cfg_attr(
+        all(not(target_arch = "wasm32"), feature = "runtime-tokio"),
+        tokio::test
+    )]
+    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+    async fn test_compare_string_adapter() {
+        let policy = "p, alice, data1, read\np, bob, data2, write";
+        let mut string_adapter = StringAdapter::new(policy);
+        let mut memory_adapter = MemoryAdapter::from_str(policy);
+        let mut model = DefaultModel::from_str(include_str!(
+            "../../examples/rbac_model.conf"
+        ))
+        .await
+        .unwrap();
+
+        assert_eq!(
+            string_adapter.load_policy(&mut model).await.unwrap(),
+            memory_adapter.load_policy(&mut model).await.unwrap()
+        );
+
+        let filter = Filter {
+            p: vec!["alice"],
+            g: vec![],
+        };
+
+        assert_eq!(
+            string_adapter
+                .load_filtered_policy(&mut model, filter.clone())
+                .await
+                .unwrap(),
+            memory_adapter
+                .load_filtered_policy(&mut model, filter)
+                .await
+                .unwrap(),
+        );
+
+        assert_eq!(string_adapter.is_filtered(), memory_adapter.is_filtered());
+
+        let string_enforcer =
+            Enforcer::new(model.clone(), string_adapter).await.unwrap();
+        let memory_enforcer =
+            Enforcer::new(model.clone(), memory_adapter).await.unwrap();
+
+        assert_eq!(
+            string_enforcer.enforce(("alice", "data1", "read")).unwrap(),
+            memory_enforcer.enforce(("alice", "data1", "read")).unwrap()
+        );
+    }
+}