LiangCN, I approve of your good work here - especially in regard to the clothing, pose, and the face. The effort and labour you put into this really shows!
Nice expression on the face - formal, but with a personality ‘behind the mask’, if you would. The expression of the eyes saves the face from being too rigid and cold… The hair is reasonable, but needs something to look more lifelike: right now, it’s a bit too much like ‘helmet hair’, if you know what I mean.
My only real gripe is with the hand - it seems a bit too large, in relation to the rest of the body. This is really an anatomical question: I could be off-base on this.
You are doing good wotk here LiangCN: keep on going, and improving your art!