What kind of documents should be prepared when a foreigner coming to China to visit his or her family members wants to apply for visa extension?

Before visa expired, no matter who you are going to visit, you need to prepare documents such as passport and residence certificate.

If he or she is a Chinese, ID card and household registration book are required for Beijing citizen. Others need to prepare the ID card and the temporary residence certificate for Chinese.

If he or she is a foreigner, residence permit or permanent residence permit are required.

If he or she is from HongKong , Macao or Taiwan, ID card and employment certificate are required.

If you are visiting your spouse, your marriage certificate is required. If you are visiting your parents or children, birth certificates are required.  If the baby was born abroad or if you got married in others countries, the birth and marriage certificate need to be certified by the Chinese embassy.