Purpose: To investigate the factors related to the development of cataract in patients with non-insulin dependent diabetes mellitus (NIDDM).Methods: 792 NIDDM patients received ophthalmologic examinations including visual acuity, external status of the eyes, slit lamp microscopy and ophthalmoscopy. Glucose, urea nitrogen(BUN), creatinine(Cr), urine acid(UA), N-acetyl-β2-D-glucosaminidase (NAG), β2-microglobulin(β2-MG) and serum albumin in blood were quantitatively tested. Glucose, pH value, protein, cells, cast and ketobodies in urine were assayed. Diagnosis of cataract was based on lens opacities classification system II. Any patient meeting “NⅡ” , “CⅡ” or“ PⅡ”level was diagnosed as cataract. Results: The incidence of cataract in this group of NIDDM was 62. 37 % (494/792), which significantly related to the duration of the disease course, but not to the sex of the patient. The occurrence rate of cataract in patients suffering from NIDDM of less than five years duration, from five to ten years, a Purpose: To investigate the factors related to the development of cataract in patients with non-insulin dependent diabetes mellitus (NIDDM). Methods: 792 NIDDM patients received ophthalmologic examinations including visual acuity, external status of the eyes, slit lamp microscopy and ophthalmoscopy. Glucose , creatinine (Cr), urine acid (UA), N-acetyl-β2-D-glucosaminidase (NAG), β2-microglobulin (β2-MG) and serum albumin in blood were quantitatively tested. Glucose, Diagnosis of cataract was based on lens opacities classification system II. Any patient meeting “NII ”, “CII ” or “PII ” level was diagnosed Results of The incidence of cataract in this group of NIDDM was 62. 37% (494/792), which significantly related to the duration of the disease course, but not to the sex of the patient. The occurrence rate of cataract in patients suffering from NIDDM of less than five years duratio n, from five to ten years, a