Abstract:The contents of soil dissolved organic carbon(DOC) in Robinia pseudoacacia Robinia pseudoacacza+Fraxinus chinensis mixed forest,Robinia pseudoacacia+Ulmus pumila mixed forest,and Robinia pseudoacacia+Uilanthus altissima mixed forest in saline land of the Yellow River Delta were studied.Among the four forest patterns,the DOC and dissolved organic N(TSN)in soil humus had significantly higher contents than those in the 0-20 and 20-40 cm soil layers, and the highest content of the DOC was founded in Robinia pseudoacana+llilanthus altissima mixed forest(257.70 mg/kg).In addition,the contents of total N(TN)and the TSN in Robinia pseudoacacia+Uilanthus altissima mixed forest were 1065.79 and 55.80 mg/kg,respectively.Soil contents of the DOC and TSN in the four forest patterns were showed as the order of Robinia pseudoacacia +Ulmus pumila>Robinia pseudoacacia+Uilanth Ailanthus altissima stand>Robinia pseudoacacia stand>Robinia pseudoacacia+Fraxinus chinensis .The DOC and TSN were significantly correlated with TN,available P,available K and salinity.