Crowdsourcing has been a prevalent measure for firms to utilize external labor and expertise in recent years. A large amount of research in this area focuses on examining the antecedents of individual solvers' crowdsourcing participation intention. However, few studies can be found to seek the motivational factors that influence the intention to crowdsource by the seeker firms. Based on the theory of transaction cost, the resource-based view and the social capital theory, this paper established a model of the influential factors of seeker firms' participation intention on crowdsourcing platform. We validate these factors using empirical data from 148 seeker firms. Analysis results indicate that all the antecedents, including the cost reduction, platform function, activeness of solvers and social relationships with solvers, exert positive effects on seeker firms' participation. Theoretical and practical implications are also discussed.