can i extend my s2 visa in china?

Yes, you can extend it at the local entry and exit management bureau. You should extend it at least 7 days before it expires.

where it is located in qingdao?what are documents required for the extension?do i need to go for a medical test?

It it is located at NO.272, Ningxia Road, Qingdao.
Tel: (86)0532-66573250 0532-66573176
Working hours: 09:00 to 12:00, 13:30 to 17:00 (Monday to Friday)
9:00-11:30 (Saturday).

The basic documents are:
1. valid passport.
2. filled application form affixed with a recent passport photo (in white background).
3. accommodation registration form or accommodation proof given by your hotel.

There are other different required documents. Your husband's resident permit, your marriage certificate and an introduction letter from your husband that includes personal information of you two, why she applies for the extension, relationship, duration of stay and a certain amount of money in your husband's bank count that satisfies your needs when you stay in China. At last, he has to sign his name on this letter. It's possible that you may be required to provide some other documents.

how much should i pay for the extension?

Hi, fee is based on nationalities actually. As I know, it should be around RMB 200-300.

do i need to change my ticket before the extension?

it is suggested to change your ticket after the extention, so that you are sure about the departure date.

hi.i dont know chinese.is there any agency/agent who can handle both english and chinese for helping me in the procedure for extension application .

I heard there are some local agencies, but I do not know their detail information.
Actually, the extension is not difficult. The staff at the extension counter can speak both Chinese and English and the application form are in both Chinese and English. So it is not so hard as you think.

can i submit all those documents through an agency without my presence?is it necessary to me to go there directly..?As my husband is busy with his job i may not be able to go there without him.thats why i am asking..

Yes, you can ask a travel agency to apply on your behalf. Both you and your husband needn't show up.

is there any local agencies in huangdao ?

one of the local agencies tell that they will provide serivice only for chinese citizen

You can consider to ask some other agencies. I am not sure about whether there are in Huangdao. Most of those agencies are located in Beijing or Shanghai, so you may need to search for more online.

Good luck with you ~

do we need to translate our marriage certificate?do i need to go for a medical test for visa renewal?

Do your marriage certificate authenticated in your country? If so, you can just use it and not translation version is needed.

The medical test is not needed for extension of X2.