A Mobile Ad Hoc Network (MANET) is a popular research topic. In this paper, we first describe characteristics of MANET, proactive and reactive routing protocols. Then AODV and DSDV, which are widely investigated in Ad Hoc network are introduced. We use simulation tool NS-2 to design three experiments to evaluate AODV and DSDV based on measure such as the packet drop rate, delays and average throughout. According to experimental results, conclusions and improvement suggestions are given to help further develop and optimize routing protocols.