The state of the commonness technique investment in the Regional Innovation Networks (RIN) directly decides the whole Regional Innovation ability. In order to analyze the characteristics of the commonness technique investment made by the manufacturers in the RIN, this article establishes an investment model in the RIN. After analyzing the model, this article puts forward a new conclusion that under the entire market investment mechanism, RIN can reduce the commonness technique investment level in the region,which makes the gap of the region with the RIN in the aspect of the commonness technique investment bigger than the gap of the region without the RIN, and the whole practical effect of the commonness technique is much greater in the regions with RIN.