Abstract: Abstract: Both architecture upgradation and service innovation are strategic drivers to advance platform ecosystem evolution, and their effects on platform development and required inputs exhibit significantly discrepancy. By analyzing the relationship between capital investment and implementation effects of the two development strategies, this paper constructs platform owners’ capital-profit function and users’ capital-utility function, then applies game theory and numerical calculation method to investigate the platform dominant development strategy choice problem. Results have shown that: (1) combination strategy of architecture upgradation and service innovation is better than any single platform development strategy being used; (2) platform companies' choice of development strategy is influenced by the whole industry characteristics, but is irrelevant to its market status in the industry; (3) when platform companies design their development strategies, they should emphasize on reducing sellers’ development cost for architecture upgradation strategy and improving buyers’ interaction utilities for service innovation strategy. These results provide ideas and guidelines for platform company’s managers to trade off and design platform development strategy.