Ignition of liquid fuel by neighbouring fire occurs occasionally in the oil storage farm. The ignition behavior is simultaneously affected by heat transfer and liquid evaporation of the unburned pool. The thermal exchange and vapor transfer involving ignition of extremely flammable liquids by neighbouring pool fire are investigated. The mean radiative heat flux of the pool to be ignited is calculated by implementing the double integration of the horizontal viewing angle coefficient of cylinder flame model. The threshold value of the incident heat flow for ignition of heptane pool decreases from 1.3 to 0.7 kW/m2 as the non-dimensional interval distance increases from d/D = 0.4 to d/D = 1.35. The radiation heat transfer by the neighbouring pool fire plays the principal role in the ignition of liquid fuel while the convection heat transfer plays the secondary role. The evaporation rate model of liquid fuel to be ignited by nearby pool fire is established according to heat transfer analysis of the unburned pool. The relative error of the experimental and theoretical value of evaporation rate of liquid fuel is within 20%. The critical vapor concentration on liquid level of ignition of n-heptane and ethanol fuel is 12.2% and 10.94% respectively.