Not illegal. Buying a house itself is not illegal, but it is illegal to operate foreign exchange. Therefore, it is not illegal to buy a house in China and pay abroad. Breaking the law refers to violating the existing laws and causing certain harm to society. Illegal acts can be divided into general illegal acts and serious illegal acts according to the seriousness of the case. According to the laws it violates, it can be divided into administrative violations, civil violations, criminal violations and unconstitutional acts. The concept of illegality has broad and narrow meanings.