In knowledge-based economy,technology licensing has become an important strategic tool for firms to gain sustainable competitive advantages. Licensing partner selection is an important part of the licensing decision. Almost all previous studies hypothesize that technology licensing contracts are signed between two independent firms， but in fact there are large numbers of technology licensing deals between two related firms， and this case is ignored by existing literature. This study focuses on the topic of licensing partner selection and examines the influences of licensors' technology structure on licensing partner selection.  Compared with previous studies， this study makes three contributions to the current literature. First， this study extends the technology licensing theory on the topic of selecting related firms as licensing partner. Second， this study analyzes the influences of licensors' technology depth and technology breadth on the decision of selecting licensing partner by introducing resource-based theory into technology licensing research. Third， this study explores the moderate effects of the technology characteristics， especially the role of number of technology which is seldom discussed by existing literature. With novel measurement of number of technology in the licensing contract， this study contributes to the empirical study of technology licensing. The results of empirical test indicate that technology depth has positive influences on selecting related firms as technology licensing partner， and technology breadth has negative influences on selecting related firms as technology licensing partner. These results partly support the traditional view that a firm with technology advantages should be active in licensing technology out. The findings reveal that technology licensing as a tool to transfer technology is more likely used by firms with greater technology depth， and as a tool to gain revenue and complement assets is more likely used by firms with greater technology breadth. Previous studies suggest that a firm should license mature technology out， and keep new technology for its own use. The results of this study indicate that the mature degree of technology can only strengthen the negative relationship between licensors technology breadth and the possibility of selecting related firm as licensing partner， and has no significant influence on relationship between technology depth and the possibility of selecting related firms as licensing partner. The results also indicate that the number of technology included in licensing contract can only weaken the positive relationship between technology depth and the possibility of selecting related firms as licensing partner， and has no significant influence on the relationship between technology breadth and the possibility of selecting related firm as licensing partner. Partly in line with previous studies， these findings reveal that a firm with greater technology breadth has stronger incentives to do active technological portfolio management， and a firm with greater technology depth has more concerns with technology spillover. This study also has some managerial implications for firms to do better licensing management. Only using patented technology data in analysis is one limitation of this research. Future researches will use nonpatent technology data to do further analysis．