Abstract: The supply-side structure of China’s agricultural insurance market has witnessed a dramatic variation since the implementation of the national premium subsidy policy. It is beneficial in ameliorating the market mechanism of agricultural insurance to study the evolution trend of supply-side structure and the periodical characteristics of market development of the agricultural insurance market. Based on the provincial panel data from 2007 to 2015, this paper developed a panel threshold model, analyzed the nonlinear characteristics amid the supply-side structural variation of agricultural insurance market and the development level of agricultural insurance, and explored the impacts of the supply-side structural variation on the development of China’s agricultural insurance. Results show that the supply-side structure of China’s agricultural insurance market imposed some nonlinear dual threshold effects on the development of agricultural insurance, dividing the provinces into 3 groups via the market structure: low concentration area (≤0.784 1), medium concentration area (0.784 1-0.982 7), and high concentration area (≥0.982 7). In addition, the evolution of market concentration of supply-side structure of agricultural insurance market of most provinces are downward trending, indicating that the decline of supply-side structural variation, or market concentration, facilitates the development of agricultural insurance market. Accordingly, this paper suggests to moderately open the agricultural insurance market to improve the operating efficiency of individuals, to develop diverse agricultural insurance products to cover diverse demands of different groups, and to strengthen the supervision of the agricultural insurance market to facilitate orderly competition.