Complicated simultaneous differential equations need to be solved as the result of non-observable quantities in the model of synchronious generator, which leads to difficulty of identification. Firstly, an identification model was derived for synchronious generator completely presented by the observable quantities, in which the quantities of state in the equation of state were represented with measurable quantity, including the outlet current of generator, exciting voltage, exciting current, power angle and increment of rotate speed. Then, the principle of direct integration least square (DILS) was utilized to identify the parameters of generator based on this model, which avoided the solution of complicated differential equation and simplified the method for parameter identification. Finally, a simulation sample was calculated in the MATLAB and the results showed that the identification model and algorithm were correct, feasible and effective.