This paper examines the effect of cooperative development project on firms’ innovative performance using ‘KIS 2010’ survey data gathered by STEPI in Korea. The analysis takes into account two factors: i) firms’ prior experience on internal and cooperative development projects, respectively and, ii) type of firms’ cooperating partners. The result shows that i) for product innovation, firms which have experienced both internal and cooperative development projects showed higher performance than those that only experienced one of internal or cooperative development project. However, for process innovation, firms’ performance was not influenced by the experience of internal and cooperative development projects. ii) Both non-academic and academic organizations’ higher participation was led to higher firm performance on product innovation, but for process innovation, only cooperation with non-academic organizations’ participation led to higher performance.