ObjectiveTo study the change and significance of the serum nitric oxide (NO) level in patient with obstructive jaundice complicated with renal dysfunction. MethodsThe level of NO, BUN, Cr in serum and the activity of NOS in 25 patients with obstructive jaundice and renal dysfunction and 26 healthy adults was studied.ResultsThe patients’ serum NO level and the activity of NOS were significantly lower than those in the control group(P＜0.01)，whereas the serum BUN and Cr levels were significantly higher than those in control group(P＜0.01). The linear correlation analysis showed that the serum NO had a negative correlation between serum BUN and Cr level (P＜0.01). ConclusionThe patients with obstructive jaundice and renal dysfunction may lead to the decrease of serum NO level. NO may have some protective effects to the renal function during obstructive jaundice.