My son doesn't have to pay back the loan guaranteed by my father. If the father still has creditor's rights and property, these creditor's rights and property should be used to repay others' debts first, and after the debts are paid off, they can inherit the remaining inheritance as heirs. Children who do not inherit their parents' inheritance need not repay their parents' debts, and those who voluntarily repay their debts are not included in this limitation.

Article 161 of the Civil Code of People's Republic of China (PRC) * * * The successor shall pay off the taxes and debts that the decedent should pay according to law within the actual value of the acquired estate. The part exceeding the actual value of the estate shall be voluntarily repaid by the heir. If the heir renounces inheritance, he may not be liable for paying off the taxes and debts that the decedent should pay according to law. Article 162 The execution of a legacy shall not prevent the legator from paying off taxes and debts according to law.