To investigate the structure and evolution of urban breeze circulation in a mountain city, we used the Weather Research and Forecasting model (V3.9) to simulate the typical urban breeze circulation from August 17 to 18, 2016 in Chongqing. We also analyzed the turbulent kinetic energy and turbulent fluxes during this period. The results show that the rural wind begins at 1500 BT (Beijing time) and increases as the heat island strengthens. The circulation reaches its maximum at 1800 BT and subsides at 0200 BT the next day. At 1800 BT, the horizontal scale of the rural wind circulation is about 1.5–2 times that of the urban area, with a vertical scale of about 1.3 km, a horizontal wind speed of about 2–4 m s^?1, and a maximum rate of increase of about 0.5 m s^?1. Due to the influence of the topography, rivers, and background wind, the circulation is weak and has an asymmetrical structure. We also found the turbulent kinetic energy in urban areas to be obviously larger than that in nonurban areas, which means that urban areas experience stronger transports of heat and water vapor by turbulence. With respect to the relationship between turbulent fluxes and urban breeze circulation, we found that the circulation of urban breezes transports water vapor from the suburbs to the city via turbulent motion, with the turbulence supplying momentum for dissipation of the urban breeze circulation.