Abstract: Abstract: little attention has been paid on the effect of the cooperative breadth and cooperative depth of enterprise’s openness from the perspective of the cohesive characteristics of internal knowledge base and enterprise’s life cycle．To make up for such a gap，this paper attempts to reveal the differences in the effects of the breadth and depth of cooperation and the cohesion of internal knowledge networks on exploratory innovation performance at different stages of the enterprise life cycle. Based on the knowledge-based theory and the perspective of enterprise life cycle, this paper uses the panel data of 176 listed electronic information enterprises in China from 2000 to 2019 to examine the impact of enterprise innovation openness and knowledge network cohesion on exploratory innovation performance at different stages of the life cycle. The Negative Binomial Regression results show that the influence of cooperation breadth and knowledge network cohesion on exploratory innovation performance is discrepant at different stages of development. There is an inverted U-shaped relationship between the breadth of cooperation and exploratory innovation performance of enterprises at the growing stage. The breadth of cooperation has a positive impact on exploratory innovation performance at the mature stage, while the breadth of cooperation has a negative impact at the recession stage. At the growing stage, the cohesion of enterprise’s knowledge network moderates the process in such a way that when it is at a high level, an enterprise’s exploratory innovation can benefit more from a moderate level of the breadth of cooperation. And the cohesion of enterprise’s knowledge network strengthens the positive influence of the cooperation breadth at the growth stage on the exploratory innovation performance, and weakens the negative influence at the recession stage. Nevertheless, for enterprises at every stage, the depth of cooperation has a positive impact on exploratory innovation performance, and the cohesion of knowledge network positively regulates the positive effect of cooperation depth. This study contributes to the literature on the relationship between innovation openness and exploratory innovation by investigating the enterprises at different life stages. From the perspective of knowledge base structure and life cycle of enterprise, it provides a theoretical framework between enterprise innovation openness, knowledge network cohesion and exploratory innovation at different life stages, integrating external cooperative openness and internal knowledge development. Thus it will also help to enrich the theory of exploratory innovation. This study makes several practical contributions. On the one hand, in exploratory innovation activities, electronic information enterprises face different innovation environments and innovation problems, and their own knowledge base is also different at different stages of the life cycle. So they need to dynamically adjust their strategy of cooperation breadth and cooperation depth by integrating internal and external factors of the enterprise to build a differentiated innovation network. Growing enterprises should choose an appropriate breadth of cooperation, avoiding blind and over-extensive cooperation with external organizations, and strive to coordinate and integrate knowledge resources within an "effective" time and space. Mature enterprises should actively promote extensive cooperation and allocate external partners with knowledge diversification. They especially need to cooperate with the partners with cross-technological fields or heterogeneous tacit knowledge. Declining enterprises should not carry out extensive cooperation, but should refine the scope of partners, and accurately search and allocate knowledge resources within a "limited" range of time and space, especially paying more attention to the deep cooperation with strong related partners. On the other hand, no matter which growth stage the enterprises are in, they should continuously improve the cohesion structure of the internal knowledge base, increasing the effective connection between knowledge elements for higher ability to absorb external heterogeneous knowledge and tacit knowledge and integrate internal and external knowledge. It will help to let a reasonable opening strategy play a more positive role in exploratory activities. Keywords: innovation openness; enterprise life cycle; knowledge network cohesion; exploratory innovation