The red giant sea cucumber (Parastichopus californicus) is native to the west coast of North America, and is under quota fishery in the United State of America and Canada. As a result of global over-fishing of sea cucumbers and increasing market demand, it is in urgent need to develop artificial breeding of P. californicus to promote the development of aquaculture. In order to develop artificial breeding of P. californicus, the embryonic and larval development of P. californicus was observed and recorded in the present study, and the size variations of fertilization eggs, embryos and larvae were measured under a microscope. The results showed that the gonad of P. californicus could be ripened by artificial diets, and the spawning of brood stock could be induced by desiccation method, in which the artificial fertilization rate exceeded 95%. The embryonic and larval development of P. californicus can be divided into the following stages:fertilization egg, cleavage, blastula, rotary blastula, gastrula, early auricularia, mid auricularia, late auricularia, doliolaria, pentactula, and juvenile. At the water temperature of 14℃, the salinity of 30 and pH of 8, the polar body occurred in 10 to 20 minutes after fertilization, and the eggs started cleavage in 1 hour, and went into rotating blastula stage in 1 day, and went into gastrula in 2 days, and went into early auricularia in 4 days. It took a total of 15 days for fertilization eggs to develop into doliolaria stage, and 18 days to develop into juvenile stage. The auricularia P. californicus reached a maximum body length of 1125.0 μm. This is the first study on embryonic and larval development of P. californicus, which may provide scientific basis for the hatchery rearing, and artificial breeding of red giant sea cucumber.