Abstract: At present, comprehensive researches are still incomplete in terms of the overall situation, changing trends and statistical characteristics of investments in VAC (ventilation and airconditioning) systems of URT (urban rail transit) project. It is essential to conduct a statistical analysis of the investment status and changing situation of URT project VAC equipment to obtain appropriate reference indicators for VAC investments.Method: A sample database is constructed based on the composition and characteristics of VAC systems，which is categorized according to sample types and construction periods. Absolute indicators (investment per single line and investment per single station) and relative indicators (percentage in the total investment, percentage in engineering cost, and percentage in electromechanical system investment) of VAC investment in URT projects are statistically analyzed for their distribution and changing trends. Additionally, some associated factors influencing the investment in URT project VAC systems are explored.Result & Conclusion: VAC investment in URT projects ranks fifth among the 10 electromechanical system investments. The indicator of investment per single line ranges from 48 million to 239 million yuan per line, showing a declining trend. The indicator of investment per single station ranges from 4.45 million to 13.77 million yuan per station, indicating an increasing trend. The percentage of VAC investment in the total investment ranges from 0.44% to 1.23%, in engineering cost from 0.72% to 2.13%, and in electromechanical system investment from 2.45% to 8.50%. These three relative indicators exhibit a pattern of slight increase during the ′12th FiveYear Plan′ period, significant decrease during the ′13th FiveYear Plan′ period, and notable rebound during the ′14th FiveYear Plan′ period. The results of statistical characteristics analysis on both above absolute and relative investment data are closely related to sample types.