目的　探讨尿N 乙酰 β D 氨基葡萄糖苷酶 (NAG)对铅毒性肾损害早期诊断的临床意义。 方法　采用对 硝基苯酚比色法对 85名铅作业工人尿NAG活性进行测定。结果　铅作业工人尿NAG活性、尿蛋白及尿 β2 MG均显著增高。随着肾损害程度的加重 ,尿NAG活性亦随之显著增加 ,并与尿蛋白、尿 β2 MG呈显著性正相关。在铅性肾损害早期 ,尿NAG活性可先于尿蛋白、尿 β2 MG出现异常。结论　长期职业性铅接触可造成肾功能损害 ,而尿NAG可作为铅性肾损害的早期灵敏的监测指标。 Objective To investigate the clinical significance of urinary N-acetyl-D-glucosaminidase (NAG) in early diagnosis of lead-induced renal damage. Methods The urinary NAG activity of 85 lead workers was determined by p-nitrophenol colorimetry. Results The urine NAG activity, urinary protein and urine β2 MG of lead workers were significantly higher. With the aggravation of renal damage, urinary NAG activity also significantly increased, and urinary protein, urinary β2 MG was significantly positive correlation. In the early stages of lead kidney damage, urinary NAG activity may precede urinary protein, urinary β2 MG abnormalities. Conclusion Long-term occupational exposure to lead can cause renal dysfunction, while urinary NAG can be an early and sensitive indicator of renal damage in lead.