一、问题的提出。案例一：２００１年５月，刘某和杨某协议离婚，双方对财产和子女抚养权、探视权达成了协议，约定其子归刘某抚养并单独负担抚养费，杨某不承担其子的抚养费，也无权探视。几个月以后，其子因十分思念母亲杨某，要求与母亲见面，其父刘某以协议为由拒绝他与杨 First, the question raised. Case 1: In May 2001, Liu and Yang agreed to divorce. Both parties reached an agreement on the custody and access of property and their children. They agreed that their son should be recuperated by Liu and be solely responsible for their support. Yang did not assume his son’s Support, also have no right to visit. A few months later, his son was very miss mother Yang, asked to meet with his mother, his father Liu refused to agree with him Yang