Don't think you have anything to worry about there.. 

After you marry their son, there's a good chance that they'll try to make you the slave of the family regardless of how well you treat them.  Of course they're not bad to you now, because they don't want to scare you off and they want to see their son get married.   My girlfrend has a couple of workers who had in-laws that were very good to them right up until the day that they married..  Then after that their parent in-laws were absolutely terrible to them..   Expecting their daughter in-law to wash all their laundry, do the dishes, clean the floor, clean the windows, clean their home, take care of the pets, do all the shopping, cooking, etc. etc.. Then after that's all done, you go back to *YOUR* home and get to do all the above *all over again* for your husband. 

At least a couple of Chinese young women that worked for my girflriend, divorced their husbands for the sole reason that their parent in-laws were bad to them. Of course, I always only hear one side of the story, so take it as you will.

I have a different experience from the above poster. From my experience close friends and family of my wife's were harder on me before we got married than after.  It makes sense because once you are married if they love their daughter/son/friend then they should support his/her marriage and not tear it apart.  Even if they personally didn't like you before you got married, they don't want to see their loved one hurt so they typically do their best to support both of you.  So from that point of view you shouldn't worry much. 

However, the one thing you are expected to do in a Chinese family is make sacrifices for other family members.  That comes in all shapes and forms and even sometimes includes extended family like cousins, nieces, nephews, aunts and uncles.  You don't need to go overboard (different families have different levels of expectations but the foundation is there in all) but if you are able to help with something, even a small thing like helping the nieces and nephews with their English you'll earn favor in their eyes.  

It takes time to learn what they will expect of you. My in-laws are good to me, and like me very much, but they have said many, many times that I am too stubborn (this is very bad in Chinese culture!)

The thing to remember is "filial piety". You will probably be expected to listen and adhere to their desires, and if you protest, it could quite likely start a big argument. 

You have a long road ahead of you, but I wish you luck and blessings! As long as your man has your back, the road may not feel as hard.

  First you need to make a lake of cheese. In traditional Chinese culture a lake of cheese is a mark of great respect. And on it you must sail, from shore to shore, in a boat made entirely of chocolate. This will express your sweet intentions towards their daughter. If your spouse is male the boat must be made of wood. It is important in Chinese culture, in the building of a family, that the man of the house, has wood. Besides all of this, the most important thing of all, and I can't stress this enough, is that you immediately punch your father-in-law in the face. Do not be afraid, he will be waiting for, and expecting/nay, hoping for this. It is a sign that a new man has come to take the throne, and it is a welcome one. Then you must kick your mother-in-law in the c**t.