first. The mortgagee shall exercise the mortgage right within the period during which the main creditor's right is protected by law. The period during which the main creditor's right is protected by law, before the main creditor's right is determined by effective judgment, is the limitation period of action for the main creditor's right; The period of application for enforcement is when the principal creditor's right is confirmed by the effective judgment through the litigation procedure; In the case of bankruptcy of the debtor, it shall be the period for declaration of creditor's rights specified by law.
 secondly. The limitation period for applying to the people's court for protection of civil rights is three years. The limitation period of action shall be counted from the date when the obligee knows or should know that his rights have been damaged and the obligor. If the law provides otherwise, such provisions shall prevail. However, if it has been more than 20 years since the date of damage to rights, the people's court shall not protect them. Under special circumstances, the people's court may decide to extend them on the application of the obligee.
 Therefore, the limitation period of action for the main creditor's rights is three years. As long as the mortgagee claims the mortgage right to the debtor within the three-year limitation period, it will be protected. The mortgage right has only one effect, and the right will be generated after the request, otherwise the right will be extinguished.
 [Legal Basis]
 In Article 419 of the Civil Code of the People's Republic of China, the mortgagee shall exercise the mortgage during the limitation of action for the principal creditor's rights; If it is not exercised, the people's court shall not protect it.