Yes, Majority of the hotels in China offer vegetarian dishes...but you have to ask for it specifically by mentioning that you don't want any meat (Chicken, lamb, pork, beef) or fish in it. You have to mention very specifically about the varieties of the meat which you don't want.
The vegetarian meals are real delicacy in China.

I am also vegetarian and visiting ningbo....will i get veg food at ningbo? do they understand english?

i think you should first tell them you are a vegetarian-we called "素食主义者" in China,then there well be a good understanding.