The method and steps of in-door indueed breeding of Huditapes Philippinarum is discribed in this paper: The sex-matured parent elams should be air-dried for a period and then soaked in ammonia sea water by adding with diluted solution of famale sexual glannds for inducing spawingThe results obtained from the experiments are as follows: Spawning could be successful with 1/2—24 hours of air-drying. Generally, the optimun period of airdrying should be controlled within 16-hours. The range of effective concentration-of ammonia and seawater for inducing was 0.00015—0.00225N. The best results are obtained from the parent clams soaked in 0.00075N of ammonia and seawater with addition of female sexual gland solution at a concentration of 25—150mg/L for 14 hours. The sucess rate reaches to 96.2%.The characteristics for the method described above are: short cryptic period, usually within 30 minutes; high spawning rate about 72—100% during the natural spawning season high festility, The rates of fertilization, incubation and the development of larvae into the viliger stage nearly reach to 100% and they can normally develop into spats under in-door conditions.