The temperature dependence of gain in InGaAs multi stacked quantum dots (QDs) laser was investigated and compared with InGaAs single quantum well(SQW) laser. It was found that quantum dost laser showed a much better stability of gain on temperature. The gain in InGaAs QDs increases with temperature in the region from 140K to 200K. Beyond 200K the gain decreases with increasing temperature. The mechanism for the above gain characteristics was analyzed. The gain peak wavelength moves to longer wavelength range with increasing temperature and exhitits a better temperature stability compared with quantum well laser.