to apply China Permanent Residence. My husband left China 35 years ago.

It is hard for him to get the China Permanet Residence permit. According to the regulation, he need to stay constantly in China for 5 years and no les than 9 months every year, have no lineal relatives in Singapore and have to stay with lineal relatives in China. He should also have stable financial income and established residence. If he has three year's good and constant investment into China, he can try to apply for it. Anyway, other options need the applicant having special important contribution or hold high offices, etc.