Thanks ja1307. Indeed my proportions is not so correct. Your right, the eyes are too big, and the forms are not always anatomically right. I'll definitely follow your advices. I think Loomis book Successful Drawing is useful especially for perspective and anatomy construction based on mash, not for forms specifically. I have to learn construction first then move for forms... not based on Loomis. Better follow Michael Hampton's Figure drawing-design and invention.