Air quality is very important for classrooms where high density of students study for long time. Enhanced ventilation is an idea way to introduce more fresh air to classroom. Hybrid ventilation combined natural ventilation with mechanical ventilation is a economic way for ventilation improvement. factors Influencing hybrid ventilation such as heat source intensity, location of air inlet, air velocity were studied by simulation in this paper. The characteristics of temperature distribution of the classroom were also analyzed. The simulation research was validated by model experiments. A low position of air inlet in the room makes high temperature efficiency, the optimal value of the air inlet velocity is about 0.5 m/s.