A novel method is proposed to optimize EDFA+ Raman hybrid amplifiers based on genetic algorithm in this paper, and a simple fitness function is achieved according to Giles two-level approximation equations and Raman power-coupled equations. The calculated results show that a flat gain profile from 1542 to 1602 nm, with a maximum gain ripple less than 1 dB can be obtained without any gain flatten filter, by using only three Raman pump diodes with proper power and wavelength. And some useful design principles are discussed.