The ablation rates and mechanisms of typical engineering materials such as Ni, W, Ta, Cu, Si and diamond by diode pumped YAG laser were analyzed. It was found that a lot of factors such as the melting point, evaporation point, thermal conductivity and crystal structure have a big effect on the abalation rates. In almost all the cases, the materials are heated up to melting point and the evaporation is the main mechanism for laser ablation.