How about the validity of your multiple visa? If it is valid, you can exit China and enter again to activate the next 30 days stay in China. Anyway, you can get your visa extended in Shandong (your future wife's local Public Security Bureau) if you need. The visa fee is as the same as the fee for a single entry tourist visa, I don't know the exact number. Probably, you will get a single entry with 30 days stay as maximum.

Dear Ms Enid,

Thanks for replying.
My validity is till oct 2011 but each entry only entitled me for 30 days maximum. but I would like to get it extend to 90 days. Is it possible?

Where can i find the local public security bureau in shandong? She is living in Yantai, shandong.

Thanks.

Regards

It is possible, but you may not be granted a 90 days visa as you wish, and also possibly you may get again a 30 days one. So, your previous visa is ok for use, if you really do not want to leave every 30 days, you can try to go through the control and enter again without actually leaving China.