In this review the sources, structures and functions of N-acetyl-beta-D-glucosaminidase, beta - 2 microglobulin and microalbumin were explained. The importance of these spesific proteinuria in early diagnosis and prognosis of different kidney diseases were discussed also. The high stability and absence of diurinal varition of N-accetyl-beta-D-glucosaminidase indicated that this enzyme can be used as a good and sensitive indicators for kidney diseases. Keywords :