The purpose of this experiment is to develop an automatic pre-market rearing anddepuration system for hard clams and oysters to produce excellent bivalves that could beenhance global competition of shellfish industry in Taiwan. This study examines theeffects of bivalve short-term stock rearing on the growth of soft inside their shell. Theexperiment hard clams are reared in tank without substrate sediments and differentsubstrate sediments. Both hard clams and oysters are feed on different microalgae tocompare their somatic composition and taste, unsaturated fatty acid, taurine. Bacterialflora and coliform in the bivalves soft be counted by many interval of experiment periodthat the bivalve rear in continuously-flowing seawater without any food is supplied. Theflowing seawater be filtered to 1 um filters and sterilized by ozone and UV. An autocontrolledmicroalga applying pipe of short-term stock rearing system is designed and reequipped,tested in experiment period.