In recent years, many company burst out into financial scandal one after another .And most of the main reason are caused by directors of the company. Directors hollowed company with the power of itself and have been resulted in infringing small shareholders’ rights. So in this thesis, we focus on the association between board and earnings quality and take further discussion on this issue. When it comes to the factors that how the Board of Directors influence earning quality, we divided the factors into three general parts which including: outside directors, the education of board members and managing directors. By controlling the influence of discretionary accruals, the empirical results show that, the higher education level the board members had, the less likely earnings manipulate happened. And by taking more deep analysis of discretionary accruals, we discovered that the higher the professional degrees the board members had, the company's surplus policy is more conservative and tends to reducing surplus via adjusting discretionary accruals.