We have carried the experiments and analyzed the nitrate content of vegetable sample getting from the city of Weifang and Qingdao where vegetable planted in large area. The result showed that the nitrate content of all sample had not exceeded the criterion of China (GB18406.1-2001). According the regulation of FAO/WHO (1973), the nitrate content of melon, fruit and rootstalk vegetable have not exceeded the criterion, but the leaf vegetable have exceeded the criterion about 30 percentage .The vegetable nitrate content exceeding the criterion can not be eaten in rawness but can be eaten by cooked. To the same vegetable, planting open the air accumulated little nitrate than planting in the greenhouse. Fertilization in the proper proportion of nitrogen, phosphorus and potassium can decrease the accumulation of nitrate in vegetable. This paper put forward a fertilization measure to control the accumulation of nitrate in vegetable.