The effect of five different reactive dyes are dying Standand Tencel and Tencel A100.Chemical structure of dyes for exhaust ratio、fixation ratio and k/s value to changes.Experiment to discover ,exhaust ratio、fixation ration and k/s value are not the highest for molecular weight mzximum .The dye of molecular weight medium and hanve bifunctional group can to measrue exhaust ratio、fixation ratio and k/s value are the highest.