Abstract: The nuclear co-insurance and agriculture reinsurance co-insurance are two of the successful co-insurance modes in the history of China’s insurance development. Through the game analysis of the above mentioned two co-insurance applicants, this paper observes the strategy choices of the two major interest parties under such mechanism, i.e., the large-scale insurance companies holding the leading position in the market and other small insurance companies participating or potentially participating the market operation. According to the different risk characteristics and market situation of nuclear insurance and agricultural insurance, it discusses the payment function and utility level of the two parties respectively when operating cooperatively in the mode of co-insurance and mechanism, choosing independent operation, or not participating this kind of insurance operation. A conclusion has been drawn that even though the different stakeholders are in different positions, they can all achieve Nash equilibrium in their co-operation strategy under the co-insurance mode. Based on this, this paper further studies the generalities and specific characteristics of these two types of successful co-insurance, and analyzes the risk types and characteristics of the co-insurance mode, including the risk and loss being low-frequency and high-loss and lacking of big data support, disaster relief requiring inputting large amount of manpower, material and financial resources, disaster losses having significant impact on the national strategy and social stability, with typical public characteristics, demanding higher technologies, etc., then it finally draws such a conclusion that the co-insurance mode and mechanism is highly applicable for catastrophe risks and insurances.

Key words: catastrophe insurance; co-insurance applicant; nuclear insurance; agriculture insurance; game theory analysis