This paper adopts the event research method, taking samples of a total of 87 government investment alliance announcements issued by the GEM listed companies in 2011-2016, and explores the announcement reaction of corporate and government alliances. The empirical results show that the cumulative abnormal return (CAR) is positive from -4 to 4 and always keeps increasing, and the government alliance announcement has a positive market reaction. And it rose greatly on the day before the announcement day, and the government strategic alliance announcement information may be leaked in advance. The results of multiple linear regression show that the indicators such as Tobin’s Q value, equity cash flow, and common stock return rate are positively related with the cumulative abnormal return (CAR), and the statistical results are significant, all of which are related to the indicators such as stock return rate and enterprise investment value, which also indicates that investors in China’s current stock market are still focused on short-term speculation.
Keywords: Announcement Reaction, Event Research Method, Government-Enterprise Alliance