diff --git a/Searching-with-IVF-index.md b/Searching-with-IVF-index.md
index 47c1cd7..9715bbc 100644
--- a/Searching-with-IVF-index.md
+++ b/Searching-with-IVF-index.md
@@ -1,3 +1,5 @@
+The previous document `Getting started` introduced some basic usage of Milvus through Python and Node SDK. This document will introduce how to use the IVF series index to speed up the efficiency of vector retrieval.
+
 # IVF_FLAT
 
 IVF_FLAT divides vector data into `nlist` cluster units, and then compares distances between the target input vector and the center of each cluster. Depending on the number of clusters the system is set to query (`nprobe`), similarity search results are returned based on comparisons between the target input and the vectors in the most similar cluster(s) only — drastically reducing query time.