Hangzhou social security to Xiaoshan social security.

Xiaoshan and Hangzhou belong to the same city now. If co-ordination is not possible, the parties concerned may first issue a contact letter agreeing to transfer the social security relationship at the relevant social security handling office in Hangzhou, and go through the social security transfer formalities at Xiaoshan Social Security Handling Office.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.