Chatbots aim to engage users in open-domain human-computer conversations and are currently receiving increasing attention. The existing work on building chatbots includes generation-based methods and retrieval-based methods. In this paper, we focus on the second type and study the problem of multi-turn response selection. This task aims to select the best-matched response from a set of candidates, given the context of a conversation which is composed of multiple utterances<cite> (Lowe et al., 2015</cite>; Lowe et al., 2017; Wu et al., 2017 ).