According to the survey of catch in the set net along the southern coast of Zhejiang from July, 2010 to June, 2011, research and analysis on the composition of length and weight, distribution and set net in the number catches of bombay duck were conducted. The results show that bombay duck appeared every month except January and February, the distribution of body length range were 27.4-201.1 mm annually, the average was 71.4 mm, the distribution of weight range were 0.05-70.5 g annually, the average was 1.4 g. Bombay duck appeared mainly in September to October, accounting for 25.5%,39.7% and 20.8% of the weight of the sample. Average weight were 1.2 g, 1.1 g and 1.6 g.