Nitrogen, one of the most abundant elements in the Universe is a fundamental element of molecules which are crucial for life. We present here the modelling of the emission of two of the simplest nitrogen-bearing molecules, CN and NO, with a non-LTE radiative transfer code in IRAS16293-2422, a class 0 low-mass protostar. In this model, we assumed IRAS16293-2422 is formed by 2 compact, hot and dense sources embedded in a three layers of envelope.