A comprehensive study has been done to investigate the lasing characteristic of 1.31 μm GaInNAs quantum well (QW) lasers. We have varied the nitrogen (N) compositions of GaInNAs QW from 1.0 to 2.0 percentages (%) with a stepped of 0.2 %. Significant improvement of lasing wavelength, emission efficiency and output power were demonstrated with higher N in GaInNAs QW. The emission wavelength red-shifted when the N% enlarge. As formerly known, the band gap of GaInNAs is controlled by adjusting the ratio of group III (Ga, In) or group V (N, As) materials. As the N increased, the band gap will be reduced and thus increasing the emission wavelength. The average ratio of the red-shifted is 92.49 nm per N %. We believed that that the optical quality of the GaInNAs QW depends on N% and total number of N incorporated in the QW. The discussion on the devices performance will be reported further.