The purpose of the study is to analyze the effect of traffic police offsite law enforcement ,and help traffic management department improve this type of law enforcement .An Internet -based survey is conducted on 729 Chinese car drivers to study their attitudes after being penalized .Descriptive analysis ,analysis of variance and comparative analy-sis are applied to data analysis .Structural equation modeling is used to study the main influencing factors of effective law enforcement .Results suggest that the overall effect of offsite law enforcement is weak ,and there is deficiency in the pro-cedure of informing and punishment .The drivers'attitudes are significantly influenced by the duration of informing proce-dure and the type of traffic violation .The effect of offsite law enforcement is inferior to that of the field law enforcement . Analysis based on structural equation modeling indicates that the accuracy of law enforcement and the severity of penalty positively influence effectiveness .Justice of law enforcement has complex indirect influence on effectiveness ,while con-venience of fine payment negatively influences effectiveness .