Dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) are the main components of soil solution and involve in many soil processes.An experiment was carried out to study effect of wheat straw incorporation,nitrogen fertilization and transplant date management on dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) in soil solution in paddy field.Soil solution samples were obtained by centrifuging fresh soil samples.Results show that the concentration of DOC in soil solution was significantly increased at the initial stage of flooding and then decreased gradually regardless of straw incorporation.Wheat straw incorporation significantly increased DOC in the first two months of flooding,and DON,too,in the initial period.Application of inorganic nitrogen led to a decrease in concentrations of DOC and DON.The concentration of DON decreased with fertilizer nitrogen application rate increasing.When the soil was flooded in the same time,delayed transplantation of rice seedlings for three weeks significantly decreased DOM.