Based on the transformer model<cite> (Vaswani et al., 2017)</cite> , we design a novel co-attention mechanism. Our proposed mechanism consists of two symmetrical branches that work in parallel to assimilate information from two input channels respectively. Different from previously known coattention mechanisms such as (Xiong et al., 2017; Lu et al., 2016a) , our co-attention is built through connecting two multiplicative attention modules<cite> (Vaswani et al., 2017</cite> ) each containing three gates, i.e., Value, Key and Query.