Abstract Objective: To investigate the aging of Chinese population, the rising cost of health care and the economic development impact on the expenditure of basic medical insurance fund, and put forward the suggestions and countermeasures for preventing the insurance fund from “wearing the bottom”. Methods: To use multiple linear regression to analyze the relationship between the the expenditure of basic medical insurance fund and the index, such as old-age dependency rate, the per capita medical expenses，the per capita GDP， the urbanization rate and the population growth rate index, which comes from 2005-2014 years in 31 provinces. Results: The statistical analysis results show that the aging population, the rising medical costs and the economic development，these three variables corresponding to the P value is less than 0.05, which indicates the aging of the population, the rising cost of health care and economic development has a significantly influence to the expenditure of basic medical insurance fund, and the rising medical costs affects the expenditure of basic medical insurance fund most, the aging of the population less, and the economic development dose the lease. Conclusion: With the escalating health care expenditures and raising the level of increasing aging of the population, the health insurance fund expenditures will be paying out more than it takes in, resulting in the risk of the health insurance fund risk wearing the bottom. In this regard, the government as the leading should take strategic moves to reform the medical insurance system and set the level of medical security to increase health care institutions and medical institutions’ rapid to control the growth of medical expenditure.