Based on the 507 family firms listed in Small and Medium Enterprise Board, this paper examines the response of the investors to family firm controlling right risk from the perspective of IPO underpricing, and the results show that the higher price is given to the listed companies with higher centralized degree of the controlling rights by the investors at the initial day of IPO, that the higher family controlling right is, the higher IPO underpricing rate is, the much higher estimated price of the listed companies is given by the investors at the initial day of IPO when the family appoints more family members to become CEOs to enhance the controlling right, however, the investors do not take care of family controlling right risk for the companies with the family members to involve in the low management level. Therefore, Chinese investors are more inclined to regard family enterprises controlling right as the opportunity of value discovery to give much higher estimated price to the companies when practical controlling family more deeply involves in CEO level, thus, China should further perfect IPO system and perfect the related company management and external supervision mechanism so as to control the risk with equity concentration.