diff --git a/chain/src/chain.rs b/chain/src/chain.rs
index 0140c6e064..99886657f0 100644
--- a/chain/src/chain.rs
+++ b/chain/src/chain.rs
@@ -93,7 +93,7 @@ impl BlockChain {
         uncles: Option<HashMap<HashValue, MintedUncleNumber>>,
         storage: Arc<dyn Store>,
         vm_metrics: Option<VMMetrics>,
-        mut dag: BlockDAG,
+        dag: BlockDAG,
     ) -> Result<Self> {
         let block_info = storage
             .get_block_info(head_block.id())?
@@ -132,10 +132,6 @@ impl BlockChain {
             vm_metrics,
             dag: dag.clone(),
         };
-        let genesis_header = storage
-            .get_block_header_by_hash(genesis)?
-            .ok_or_else(|| format_err!("failed to get genesis because it is none"))?;
-        dag.set_reindex_root(genesis_header.parent_hash())?;
         watch(CHAIN_WATCH_NAME, "n1251");
         match uncles {
             Some(data) => chain.uncles = data,