In Hong Kong there is no official retirement age so you can stop whenever you want or carry forever. There are some restrictions though of a minimum amount of money you have to put in for your pension and you cannot use this money before you can use it.
There is Comprehensive Social Security Assistance and Mandatory Provident
Fund which is obligatory though, see there for more information:
www.mpfa.org.hk/eindex.asp
Hong Kong like a lot of developed countries faces a problem of ageing population. This explains the important role of the Mandatory Provident Fund in contributing towards the financial security of Hong Kong's working population in their retirement years.