Abstract: Recently, two-way relaying (TWR) has received much attention as a powerful approach to improve the spectral efficiency of the relaying networks. In this paper, the outage performance of three-time-slot TWR protocol with co-channel interference was analyzed, where the relay adopts the amplify-and-forward protocol. The lower bound and asymptotic expressions of outage probability were derived in closed-form and were shown to provide a good approximation to the exact performance. With the theoretic results, the power allocation at the relay and relay location were optimized in order to minimize the outage performance. Three optimization problems were proposed, i.e., 1) the optimal power allocation at the relay with fixed relay location, 2) the optimal relay location with fixed power allocation at the relay, 3) joint optimization of power allocation at the relay and relay location. The results show that the joint optimization scheme can achieve the best performance.