Abstract: Analysis of plutonium in urine is the primary method to calculate the irradiation dose of plutonium handlers. The chemical pre-treatment precedure for analysis of trace level plutonium in urine were inveitigated. The optimized conditions were follows as: acidity of 7-8 mol/mL, adsorption rate of 0.5-0.8 mL/min, desorption rate of 0.2-0.3 mL/min, desorption solution of 10 mL, pulse plating current of 0.5 A, current frequency of 2 000 Hz, duty ratio of 1∶2 and plating time of 2 h. The whole recovery of 66.0% for ²³⁸Pu of 4.23×10^-3 Bq could be achieved with much less analysis time and 10%-15% higher recovery than the ordinary precedure.