Objective: to analyze the changes of the income and expenditure balance of urban basic medical insurance fund in China, and to evaluate the time and extent of the occurrence of the risk. Methods: according to the income, expenditure and accumulated balance of the basic medical insurance fund of our country from 1995 to in 21 years, the time series model was used to forecast the balance of income and expenditure in the year of 2025 and in the year of 2030. Results: the basic medical insurance fund in our country the burden coefficient from 34.28% in 2007 to 35.25% in 2015; the number of retirees increases with increasing the number of staff proportion soared from 24.35% in 2007 to 85.98% in 2015; the fund expenditure coefficient increased from 0.63 in 2001 to 0.83 in 2015. Conclusion: with the increasing trend of aging in China, the rapid growth of medical expenses, the balance of urban medical insurance fund balance pressure is increasing, it is predicted that by 2021, the fund will have the risk of overspending