Entry permission of china travel visa

Dear sir or mdm., good morning. I am a hong kong citizen holding a valid china visa. But it will be expired on the 20th March. I want to go China travelling for 3 days around March 1st to 10th. However travelling within this 10 days , is it valid for entry and out of China? If yes or no, please let me know what's going on to do. Thank you very much.