The debate of gender diversity on boards becomes more and more popular all over the world. Male dominant on boards is very serious in Hong Kong and China listed companies. The relationship between gender diversity on boards and firm financial performance in different countries is worth to be investigated. This study examines the relationship between gender diversity on boards and firm value in Hong Kong and China. Further, the relationship between the proportion of independent directors and Tobin’s Q, influence of Female CEO on the effect of female directors ratio on Tobin’s Q, influence of Board Independence on the effect of female directors ratio on Tobin’s Q, and the influence of Board Size on the effect of female directors ratio on Tobin’s Q are also investigated in this study. These relationships are examined by using the financial data, corporate governance data, board directorship data and firm characteristic data in Hong Kong and China Main Board firms from the year 2001-2009. Correlation and regression analyses indicate that gender diversity on boards and board independence are positively related to firm financial performance measured by Tobin’s Q in Hong Kong and China. Further, Female CEO has gender preference on directors in Hong Kong and China shares market. Board independence can strengthen the effect of female directors ratio on Tobin’s Q and larger board size weakens the effect of female directors ratio on Tobin’s Q in China shares market.