This paper explores the empirical results of the implementation of an independent director system in China, and identifies the advisory role of the board. The results show that firms implement board independence by adding extra members, instead of removing inside directors, except in the case where the board size (before the recruitment of independent directors) has already been too large. It has been found that complex (large and diversified) firms prefer a large board with more independent directors on the board. However, the largest shareholders have a strong incentive to organise a small and insider-controlled board. Although there is a negative relationship between board size, board independence and firm performance, Tobin’s Q increases in relation to board size and board independence for complex firms.