After the new underwriting methods from 2016, this paper analyzes the underlying stock returns of convertible bonds (CBs) under book-building and auction methods by using the first issuance information of CBs from market observation post system. The empirical results show that, under book-building method, the average annual stock return from the next trading day of the first issuance information of CBs to CB listing date is higher and up to 34.05%. Under auction method, the average annual stock return from the next trading day of the first issuance information of CBs to CB bidding date is higher and up to 22.35%. Under book-building method, the average annual stock return from the next trading day of the first issuance information of CBs to one year hold return is positive.