Abstract: This study examines the interplay between firms' R&D behavior, R&D fields and patent quality, utilizing a sample of 136,484 invention patents that Chinese listed companies applied and got approved for between 1988 and 2017. Firstly, we construct the relationship between exploration and exploitation R&D behaviors and the depth and breadth of R&D fields at both project and field levels, measured from the perspective of technology boundaries. Secondly, we apply a text analysis method to measure patent quality. Lastly, we analyze the balanced relationship between exploration and exploitation and its optimal combination with the depth and breadth of R&D fields, and explore the impact of R&D behaviors of firms under different technology fields on patent quality. The findings of this study indicate that:(1) a balanced approach with exploitation as the main focus and exploration as the supplement is most conducive to improving patent quality; (2) the breadth of R&D fields has a negative impact on patent quality, while depth exhibits an inverted U-shaped impact; (3) the breadth and depth of R&D fields have different moderating effects on the relationship between exploitation and exploration behaviors and patent quality; and (4) the impact of different R&D behaviors on patent quality differs across various technology fields.

Key words: R&D behavior, exploration-exploitation, R&D field, patent quality, technology boundary