Abstract: Objectives To investigate the factors influencing the rule of formaldehyde released from indoor floor board.Methods The concentrations of formaldehyde releasing from high fiber wood floor board, composite solid wood floor board and bamboo floor board for different environmental factors, such as temperature, humidity, loading ratio or ventilation rate were investigated in an environmental test chamber, and the experimental data was fitted with the single index model.Results The concentration of formaldehyde released from floor board increase with the rise of temperature, humidity and loading ratio; and the concentrations of formaldehyde in the air of environmental chamber decrease with the rise of ventilation rate. The concentrations of formaldehyde released from high fiber wood floor board exceed the national standard limits when the temperature was over 15℃,the loading ratio was over 0.5 m²/m³, the humidies were 35%～75%, and the ventilation rates were 0.5～1.5 times perhour. The highest concentration of formaldehyde released from high fiber wood floor board was 0.420 mg/m³, which was 4.2 times that of the national standard limit. The relationship between the concentration of formaldehyde released from floor board with the temperature, humidity of indoor air and loading ratio were in agreement with the single index model, and the maximum R² would be 0.99968.Conclusions High temperature and high humidity environment can promote the release of formaldehyde from floor board in indoor.