[Objective] The research aimed to evaluate the phosphorus balances in the main crop production systems in Shunyi District of Beijing City.[Method] By using the nutrient budget method,the phosphorus balances in the main crop production systems（field crops,orchard and open-field vegetables） in Shunyi District of Beijing City were evaluated.Moreover,the main influence elements of phosphorus surplus in the farmland were analyzed.[Result] The positive phosphorus balances were found across all three crop production systems in the study period.The amount of phosphorus surplus [491.8 kg/（hm2·a）] in vegetables production system was significantly higher than that in field crops [82.7 kg/（hm2·a）] and orchard [129.5 kg/（hm2·a）] production systems（P0.05）.But the amount of phosphorus surplus between the latter two had no significant difference（P0.05）.Phosphorus surpluses in the production systems of field crops and vegetables respectively presented the extremely significant and positive relationship with the phosphorus input from chemical fertilizer and organic fertilizer（r was respectively 0.987 7 and 0.970 1）.The phosphorus input from chemical fertilizer and organic fertilizer in the orchard production system both presented the extremely significant and positive relationship with the phosphorus surplus in the farmland（r was respectively 0.836 3 and 0.625 2）.However,the phosphorus harvested by crops didn＇t significantly correlated to the phosphorus surplus in the farmland for all three crop production systems（P0.05）.[Conclusion] The risk of phosphorus pollution potential in all three crop production system of Shunyi Distirct was high,especially in the vegetable production system.The phosphorus surpluses in the production systems of field crops and vegetables were mainly from the inputs of chemical fertilizer and organic fertilizer,respectively.However,the inputs of chemical fertilizer and organic fertilizer both significantly affected the phosphorus surplus in the orchard production sy
