Base on panel data of manufacturing and high-tech industry companies which discoursed R & D expenditure in financial statements from 2004 to 2011, this paper studies the relationship between debt financing and corporate R & D expenditure under different grow opportunities by using the robust fixed effects that Daniel Hoechle proposed in 2007. The results show that there is not a "increasing first, decreasing later" non-linear relationship but a "double negative" relationship between debt level and corporate R & D expenditure. And the "double negative" relationship has a different mechanism in different growth companies.