Objective To understand the content of disinfection by-products in urban drinking water of a district,Shandong Province,and to evaluate their health risk. Methods From 2018 to 2022,a total of 90 water samples of urban drinking water were collected from a district of Shandong Province during dry and abundant water periods,respectively.Disinfection by-products were tested according to GB/T 5750.10-2006 Standard examination method for drinking water-Disinfection by-products parameters.Evaluate in GB 5749-2006 Standards for drinleing water guality the health risk model recommended by the US Environmental Protection Agency was used for risk evaluation. Results The qualified rate of disinfection byproducts was 76.67% in a district of Shandong Province from 2018 to 2022.The exceeding indicators were trihalomethanes and trichloroacetaldehyde,with exceeding rates of 23.33% and 4.44%,respectively.Except for cyanogen chloride,methylene chloride and 2,4,6-trichlorophenol,which were not detected,all other disinfection by-product indicators were detected to varying degrees.The contents of trihalomethane,trichloromethane and bromodichloromethane were higher in the abundant water period than those in the dry water period (P<0.05).There was no statistical significance in the contents of disinfection by-products between the effluent water and the final water (P>0.05).The carcinogenic risk of by-products of drinking water disinfection in this area is in the range of 1.0×10^-6-1.0×10^-4.The carcinogenic risk of chlorodibromomethane and dichloroacetic acid at individual monitoring sites was ＞1.0×10^-4.The non-carcinogenic risk of each disinfection by-product was＜1.0. Conclusion The non-carcinogenic risk of disinfection by-products of urban drinking water in a district of Shandong Province is within the acceptable range.However,the carcinogenic risk should be given high priority,especially dichlorodibromomethane and dichloroacetic acid are the key risk management indicators.