This study investigated the effect of rearing conditions on the spawning habit, juvenile growth and larvae development of Marphysa sanguinea, to develop techniques of its artificial seed production. M. sanguinea released trochophore larvae around the burrow when the water temperature was from $18^{circ}C$ to $22^{circ}C$. Larvae floated away after staying in the burrow for a while. Larvae secreted mucus eight days after release, covering their whole body with it, and developed ten somites 20 days after release. In preference of juveniles in different grain sizes of sediment, the highest survival rate was made in the grain substrate of $1{sim}2$ mm in the mean diameter, but the lowest was in the $2{sim}3$ mm grain substrate. Optimum growth was obtained at the rearing temperature of $24^{circ}C$(SGR 1.10%), and it reached over $2{sim}3$ times higher weight gain and specific growth rate than those reared at $21^{circ}C(0.64),;18^{circ}C(0.56)$ and $15^{circ}C$(0.42) for 50 days. Salinity also made a great difference in the growth and survival rate. The highest weight gain and growth rate were shown when the juveniles were reared at salinity 30 psu.