Abstract: Through field investigation, sampling and measuring of surface fuel characteristics of four main forest types in Kunming, flame experiments were carried out in the laboratory to determine the ignition time, flame holding time, maximum height of flame, maximum temperature, flame colors and thermal radiation. The results shown that：（1）the fuel loads of Pinus armandii forest,Pinusyunnanensis forest, Quercusacutissima forest, and Cupressusfunebris forest are 3.37 kg/m2, 2.35 kg/m2, 2.24 kg/m2, and 1.47 kg/m2, respectively.（2）The colors of the flames are dull red and the ignition time of cypress and Quercusacutissima is 3 s, while that of Pinusyunnanensis and Pinusarmandii is 1 s, which should be easily ignited. The longest flame duration was 6.34 min for Pinusarmandii, 3.89 min for Quercusacutissima, 3.45 min for Pinusyunnanensis and 2.28 min for cypress. The maximum flame height of Quercusacutissima is 90cm, Pinusyunnanensis 70 cm, Pinusarmandii 50 cm and cypress 20 cm. The highest flame temperature of Pinusyunnanensis is 897.5 ℃ , cypress 877.5 ℃ , Quercusacutissima 657.5 ℃ , and Pinusarmandiiis 563.3 ℃ . The maximum flame depth of Quercusacutissima is 105 cm, Pinusyunnanensis 85 cm, Pinusarmandii 63 cm and cypress 35cm. The maximum thermal radiation of Quercusacutissima is 7.31 kW/m2, Pinusyunnanensis 6.92 kW/m2, Pinusarmandii 6.70 kW/m2 and cypress 3.18 kW/m2. The flame characteristics of surface fuel of four main forest types around Kunming are very obvious, which is worthy of further studying.The results of this research are helpful to better grasp the characteristics of surface fuel and heat release law of main forest types around Kunming, and to carry out fire prevention management more scientifically and reasonably.

Key words: flame height, flame temperature, flame radiation, surface fuel