Abstract: Objective To present the method for determining acetaldehyde,acrolein in source water directly in same time.Methods The gas chromatography rapidity and sensitivity and fairly good precision was used.Results The detection limits were 0.2ng,0.452ng for acetaldehyde,acrolein.The rates of recovery were 94%-102.4% and coefficients of variation were 4.15%-5.46%.Conclusion This method can be up to the requirement of sanitary standards for drinking water.