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Removing cadmium from waste water before it flow out of factories is critical for protecting human health.Although some researchers have constructed some engineering bacteria to remove cadmium from waste water,the engineering bacterias resistance to cadmium had not been improved.This made it hard to use these engineering bacteria in real cadmium removing from waste water.In this study,gshB,gshA,cysE,TcPCS1 and TcHMA3 were transformed into E.coli BL21.The resistance to Cd of the engineering bacterium was significantly higher than that of the initial bacterium.The cadmium accumulation in the engineering bacterium was also much higher than that in the initial bacterium.The cadmium-resistance of bacterium ABEP(transformed with gshB,gshA,cysE and TcPCS1)was significantly higher than that of AEP(E.coli BL21 transformed with gshA,cysE and TcPCS1),demonstrating that gshB played key roles in glutathione synthesis and the step catalyzed by glutathione synthase was limiting for production of phytochelatins.The cadmium content in AEP was higher than that in E.coli BL21 transformed with gshA,cysE and SpPCS1(a yeast phytochelatin synthase),showing that TcPCS1 had more specificity and higher capacity to remove cadmium than SpPCS1.The cadmium accumulation in ABET3P was higher than that in ABEP,demonstrating that TcHMA3 not only can play roles in Thlaspi caerulescens,but also can function in E.coli.