diff --git a/core/api/src/schema/epoch.rs b/core/api/src/schema/epoch.rs
index 021243109..bd58314c8 100644
--- a/core/api/src/schema/epoch.rs
+++ b/core/api/src/schema/epoch.rs
@@ -23,7 +23,7 @@ pub struct EpochHeader {
     pub chain_id: Hash,
     #[graphql(description = "Known as the block height like other blockchain")]
     pub epoch_id: Uint64,
-    #[graphql(description = "The merkle root of the previous epoch")]
+    #[graphql(description = "The hash of the serialized previous epoch")]
     pub pre_hash: Hash,
     #[graphql(description = "A timestamp that records when the epoch was created")]
     pub timestamp: Uint64,
diff --git a/core/api/src/schema/transaction.rs b/core/api/src/schema/transaction.rs
index ea82a1c0c..cc182258c 100644
--- a/core/api/src/schema/transaction.rs
+++ b/core/api/src/schema/transaction.rs
@@ -5,7 +5,7 @@ use crate::schema::{Address, AssetID, Balance, Bytes, Hash, Uint64};
 pub enum ContractType {
     // Asset contract
     #[graphql(
-        description = "Asset contract often use for creating User Define Asset(also known as (User Define Token))"
+        description = "Asset contract often use for creating User Define Asset(also known as UDT(User Define Token))"
     )]
     Asset,
     // App contract, the code in the contract is allowed to change the state world.