Taking the levy on the houses in our urban construction as the example,the law rules must solve the two-side of drive questions: the property owner and the levying at the same time.The conclusion of gambling analysis was drawn that only when the law rules are changed or court judges change the anticipation of main body's action,will the balanced result in the domain execution of the law be altered.Whether the law rules are efficient or not depends on the court system and ability.Economics is changing the law structure and the foundation of implementation.