Pot and filed experiments were conducted to study the Pb and Cd contents in soil and plants during soybean growth periods under the treatments of different residual amounts of mulching plastic film.Results showed that during soybean growth periods,the Pb and Cd contents in soil and the plants for high residual mulching film samples were higher than those for low.The Pb contents in soil were 49～188mg/kg;the Cd contents in soil,0.7～2.4mg/kg;the Pb contents in plants,0.022～0.097mg/kg;and the Cd contents in plants,0.001～0.0032mg/kg.By the secondary limit of China Environmental Quality Standards for Soils(GB15618-1995),the Pd content in soil was less than the limit and the Cd content in soil was higher than the limit.By the China Maximum Levels of Contaminants in Foods(GB2762-2005),the Pd and Cd contents in seeds were less than the level and the Cd content in seeds was much less than the level.