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Heavy metal contamination in soils has been a severe issue in agricultural production around the world in the past few decades because of its high health risk through soil-food chain transfer. A sudden emergence of heavy metal tainted rice from the South China market urged countermeasures to prevent heavy metal uptake and accumulation in rice from heavy metal contaminated rice paddies. To investigate and quantify the effects of combined application of biochar (BC) and nitrogen fertilizers on the growth, yield and heavy metal uptake of rice (Oryza sativa L.) on a historically multi-metal contaminated paddy soil, the pot experiments under waterlogged condition were carried out in a greenhouse and five different treatments were compared including control soil, soil only with common nitrogen fertilizer ammonium sulphate nitrate (ASN), soil only with nitrogen fertilizer ammonium sulphate nitrate with nitrification inhibitor 3,4-dimethylpyrazolephosphate (DMPP), soil both with biochar and common nitrogen fertilizer, and soil both with biochar and DMPP nitrogen fertilizer. Both soil and rice plant samples were collected after rice harvest. Available heavy metals of soils, roots, straws and grains of rice were analyzed. The results showed that nitrogen fertilizer with nitrification inhibitor DMPP had no significant (P>0.05) effect on rice grain yield if they were not used in combination with biochar. Biochar combined with common nitrogen fertilizer or DMPP nitrogen fertilizer could significantly (P<0.05) increased the grain yield. Compared with the single application of common nitrogen fertilizer, the grain yield of rice in the treatment with combined use of biochar and common nitrogen fertilizer was significantly (P<0.05) increased by 20.3%. Compared with the single application of DMPP nitrogen fertilizer, the grain yield of rice in the treatment with combined use of biochar and DMPP nitrogen fertilizer was significantly (P<0.05) increased by 49.3%. Compared with the control, the concentrations of Cu, Zn and Cd in grain of in the treatment with combined use of biochar and DMPP nitrogen fertilizer were significantly (P<0.05) decreased by 20.0%, 21.4% and 11.6%, respectively. DMPP could promote the transfer of Cu from straw to grain when biochar was not applied together, but promote the transfer of Cu and Cd from root to straw when biochar was used together. The effect of combined application of biochar and nitrogen fertilizer on transfer of Cu and Cd varied with different nitrogen fertilizer. The results above indicated that combined application of biochar and DMPP nitrogen fertilizer could promote rice growth, increase the yields of rice grain and decrease its heavy metal Cu, Zn and Cd concentrations. The results further suggested that in a multi-contaminated watterlogged paddy soil, biochar and DMPP nitrogen fertilizer could be adopted together. This study demonstrated the application of both biochar and DMPP nitrogen fertilizer could prevent dangerous heavy metal accumulation in heavy metal contaminated paddy field. [ABSTRACT FROM AUTHOR]