The results of parameters identification are usually imprecise due to the data error. In order to illustrate the influence, based on six order model of the synchronous generator, the sensitivity of the parameters and the data errors is studied. Firstly, a model between the steady parameters and transient parameters and the data errors are built respectively, and then the upper bound estimates of the sensitivity between the parameters and the data errors are derived. Using the proposed analysis method and taking current error for example, a numerical example of estimate equation of calculation parameter to data error is given based on the PMU current data. The conclusion shows that influence degree of current data error to synchronous generator parameter in order is static parameters, transient parameters and sub-transient parameters. This work is supported by National Natural Science Foundation of China (No. 51577060).