Abstract: The objective of this study was to investigate the deposition and depletion of melamine in different tissues of laying ducks. Four hundred and thirty-two 19-week-old Jinding laying ducks(Body weight:1.66±0.16 kg, egg production:75.15%±3.29%) were randomly divided into 4 groups with 6 replicates of 18 birds each. Each group was fed a corn-soybean meal diet supplemented with 0, 5, 50 and 100 mg·kg^-1 melamine respectively for 21 d. The melamine concentration in the plasma, kidney, liver and breast muscle were determined on day 4,7,14 and 21 d. After switching the basal diet for 8,24,48 and 96 h the melamine content were determined in the plasma, kidney, liver and breast muscle samples. After adding melamine to the dietary for 21 days, the average melamine in different tissues of 50 and 100 mg·kg^-1 melamine treatment groups were significantly higher than that of 0, 5 mg·kg^-1 melamine treatment groups(P<0.05), there was no significant difference between 0 and 5 mg·kg-1 groups（P>0.05）. The melamine concentration in tissues of 100 mg·kg^-1 group decreased progressively by the order of plasma> kidney>liver>breast muscle. Higher dietary melamine concentration requires a longer time to eliminate from the tissues. After withdrawing melamine diets for 96 h, the melamine concentrations in different tissues were decreased significantly, but the melamine in different tissues can not be completely eliminated in 96 h. Cyanuric acid had not been detected in the tissues of laying ducks. The melamine concentration in the different tissues were increased with the levels of melamine in the diet, and showed doseresponse relationship. Melamine needs a long duration, which can be demonstrated by the incomplete elimination of melamine in the tissue within 96 h. Melamine concentrations in plasma and kidney were higher than that in liver and breast muscle. The study indicates that plasma and kidney can be used as the indicator for the residue of melamine. The depletion time for melamine in different tissues should be longer than 96 h.