Hot mixed asphalt (HMA) in the paving and rolling phase may release all types of volatile organic compound (VOC) pollutants, but there are few studies on VOC emissions from in situ asphalt pavement mixtures. The purpose of this study was to evaluate the cooling variable effect on in situ new and recycled asphalt pavement (RAP) on VOC emission. Determination of VOCs in samples can be made by a gas chromatography mass spectrometer (GCMS). The results showed that the end temperature of RAP was about 5 ℃ lower than that of a new asphalt mixture during the cooling process. It required a longer amount of time for natural aggregate mixtures to lose heat and thus required more time for the pavement to be closed to traffic. After cooling to about 90–100 ℃, the pavement temperature gradient decreased gradually, indicating that the asphalt pavement mixtures’ temperatures in the 90–100 ℃ range gradually reached a steady heat transfer process. In addition, higher temperatures affected the VOC emissions from any reclaimed asphalt mixture. The asphalt mixture continued to cool to below 100 ℃, and the acetone emission concentration gradually decreased. It was indicated that the temperature must be less than 100 ℃ for asphalt pavement mixtures to reduce the risk of harm to human health.