This paper addresses the consensus problems for two kinds of hybrid multi-agent systems. The first kind of hybrid multi-agent system is composed of first-order discrete-time and second-order continuous-time dynamical agents. Based on different interactive modes, two effective protocols are presented for the hybrid multi-agent system, respectively. By using graph theory and system transformation method, some criteria are obtained for solving the consensus problem. The second one consists of first-order continuous-time and second-order discrete-time dynamical agents. The effective protocols are also proposed to guarantee the consensus. Meanwhile, the necessary and sufficient conditions are established for solving the consensus problem. Simulation examples are provided to demonstrate the effectiveness of theoretical results.