providing proof of employment and show money

Hi! My Chinese friend invited me to visit China for 5 days. with regards to this, do I still need to provide a proof of employment or bank statements just to make sure that I won't be over staying or work there illegally? Or I just have to ask my friend to provide her bank statements to prove that she will be able to assist my needs when I get to PRC? I would really like to know.
Thank you so much!