An experiment was conducted to estimate optimal dietary arginine requirement in White Pekin ducks from 1 to 21 d of age. Six hundred thirty 1-d-old male White Pekin ducks were randomly allotted to 10 dietary treatments with 7 replicate pens of 9 birds per pen. Birds in each group were fed corn-corn gluten meals diet containing 0.71, 0.84, 0.95, 1.03, 1.17, 1.27, 1.39, 1.47, 1.62, and 1.72% arginine, respectively. At 21 d of age, weight gain, feed intake, feed/gain ratio, and breast meat yield from each treatment were measured. Dietary supplementation of arginine significantly improved weight gain, feed intake, feed/gain, and breast meat yield (P < 0.01). Based on quadratic broken-line regression analysis, the arginine requirement of male White Pekin ducks from 1 to 21 d of age was 0.95, 1.16, and 0.99% for weight gain, feed/gain, and breast meat yield, respectively.