This study analyses the factors that determine agricultural R&D performance, which thereby contribute to enhancing the efficiency of agricultural R&D investment and the resulting performance. R&D performance is measured by four indices: patent registration, SCI publication, technology transfer, and on-site agricultural application. The affecting factors include the variables that relate to the input of R&D resources and the R&D system. The empirical analysis was conducted by using Poisson regressions, using the survey data of the R&D projects that the Rural Development Administration (RDA) had completed during the years 2004-2006. According to the empirical findings, the qualitative characteristics of the R&D workforce are the primary determinants of agricultural R&D performance regardless of performance measures, while the impact of quantitative aspects of R&D resources vary depending on the type of performance measures. The quality enhancement of the R&D workforce should be thus given a top priority to induce better R&D performance in the agricultural sector.