Abstract: A total of 864 day-old female meat ducks were fed one of six diets in a 2 (0 and 0.5 g betaine/kg)×3 (0, 0.6, 1.2 g methionine/kg) factorial arrangement between 0 and 41 days of age. There were six replicates of 24 ducks per treatment.The results of rearing trial showed that there were no significant interactions between betaine and DL-methionine.betaine is more effective in improving carcass quality than methionine, and also effective in promoting growth and feed efficiency of starter ducks, provided the dietary levels of methionine are not marginally limiting. The results implied that the betaine can enchance synthesis of carnitine by improving methylation metabolism and stimulate the B-oxidation of long chain fatty acids in the inner mitochondria membrane of muscle cells.