Burning characteristics of small scale thin-layer n-heptane pool fires were experimentally studied.Flame height,burning rate and fuel temperature distribution of pool fires with different diameters were measured.Fuel surface temperature and wall heat flux were analyzed.Four typical burning phases,which include pre-burning,quasi-steady state burning,boiling burning and decaying phases,are revealed based on the experimental data and phenomenological analysis.It is shown that flame height and burning rate of boiling burning phase are both significantly greater than those of quasi-steady state burning phase.Fuel surface temperature rises to boiling point rapidly in the early stage of pool fire,and then remains almost unchanged.Boiling burning will occur when the wall temperature is not less than the fuel boiling point. Burning characteristics of small scale thin-layer n-heptane pool fires were experimentally studied. Flame height, burning rate and fuel temperature distribution of pool fires with different diameters were measured. Ferrous surface temperature and wall heat flux were analyzed. Fire typical burning phases, which include pre-burning, quasi-steady state burning, burning burning and decaying phases, are revealed based on the experimental data and phenomenological analysis. It is shown that flame height and burning rate of boiling burning phase are both significantly greater than those of quasi -steady state burning phase. Fuel surface temperature rises to boiling point rapidly in the early stage of pool fire, and then remains almost never.Builing burning will occur when the wall temperature is not less than the fuel boiling point.