In order to predict weld profile of T- joints and optimize the process parameters of the laser full penetration welding, the statistical models between parameters and the weld bead geometry of T- joints are established using response surface methodology. Then the analysis of variance is checked and these mathematical models are validated. Based on this model, effects of different process parameters on the weld profile are investigated, the process parameters are optimized, and the weld profile is predicted. The results indicate that the proposed models predict the responses adequately and the predicted values are consistent with experimental results. The optimum welding conditions are found that it can reduce the heat input about 27%.