Abstract: In this paper,first order gratings for InP based distributed feedback quantum cascade lasers （DFB-QCL） were fabricated by holographic lithography and wet chemical etching. The etching process was optimized for small patterns and good grating profiles. DFB QCL operating at room temperature in pulsed mode was demonstrated with a high side mode suppression ratio of about 30dB. The device results indicate the high quality of gratings.