Abstract: 【Objective】The study was conducted to investigate the effect of different nitrogen forms on the quality of mini Chinese cabbage cultivated on substrate,providing scientific reference to nitrogen fertilizer application in Brassica pekinensis cultivation on substrate.【Method】The experiment was conducted in pots with substrate.Four nitrogen forms and proportions were set with no fertilization as the control（CK）,i.e.,the total ammonium nitrogen （T₁）,50%ammonium nitrogen and 50%nitrate nitrogen （T₂）,the total nitrate （T₃） and urea （T₄）,which had the same level of total nitrogen.After harvesting,the contents of soluble sugar,soluble protein,VC,nitrate,titratable acid and mineral elements were determined.【Result】Application of ammonium nitrogen significantly increased the content of soluble sugar in mini Chinese cabbage.Compared with the CK,the soluble sugar of the treated plants in T₁ and T₂ significantly increased by134.1%and 48.35%,respectively.The combined application of 50%ammonium nitrogen and 50%nitrate nitrogen significantly increased the contents of soluble protein and VC in mini Chinese cabbage in comparison with other treatments.The fertilization increased the nitrate level in mini Chinese cabbage,and the nitrate content in different treatments ranked as following:T₃＞T₂＞T₁＞T₄＞CK.It was more likely that Nitrate nitrogen caused the increase of nitrate level in B.pekinensis,and that the combined application of ammonium and nitrate nitrogen reduced the nitrate content.The effect of nitrogen forms on the mineral element contents was inconsistent among different treatments.The contents of K,Ca and Mg were the highest under the treatment with total nitrate nitrogen,which increased 161.9%,30.7%and 68.2%,respectively,compared with the CK.The 50%ammonium nitrogen and 50%nitrate nitrogen were favorable to N,P,Mn and Zn accumulation,and the contents of Cu and Fe were the highest under total ammonium nitrogen treatment.【Conclusion】The combined application of 50%ammonium nitrogen and 50%nitrate nitrogen significantly increased the contents of soluble protein and VC in mini Chinese cabbage,of which the soluble sugar content is higher and the nitrate content is lower.Therefore,the treatment was beneficial to nutrient accumulation and quality,and the results could be used as a reference for nitrogen fertilizer application in the substrate cultivation of mini Chinese cabbage.