Abstract: Based on theories of environment alignment and dynamic capability, this paper conducts questionnaire survey of 248 Chinese start-ups, and examines the mediating effect of the different organizational agility during the process that open innovation proclivity influences the improvement of the liability of newness, and the moderating effects of the two types of network structure in the process. The results show that: (1)Through the mediating effect of organizational agility, the open innovation proclivity can improve the liability of newness in Chinese start-ups. (2)the organizational agility, especially the customer agility and partner agility , have important intermediating effect in the process which open innovation proclivity influences the liability of newness. However, statistics showed that operational agility has failed to have intermediating effect in that process.(3) Network structure plays an important moderating roles in the mechanism that open innovation proclivity influences the organizational agility of the start-ups. Under the different level of network closure and structural hole, the open innovation proclivity makes different effect on the organizational agility of the start-ups. The paper theoretically meets the research gap of the improvement mechanism of the liability of newness, , further validating the effectiveness of the construct of the liability of newness, enriches and expands the open innovation research in the entrepreneurial context.