There are more interests in better understanding kitchen fires with multiple burning sources in this paper because of the demand in the construction industry. Computational Fluid Dynamics (CFD) was applied to study kitchen fires with multiple burning sources using experimental data reported earlier. A room of length 3.6 m, width 2.4 m and height 2.4 m was constructed with a door of width 2.0 m and height 1.9 m to provide natural ventilation. Chinese frying pans of diameter 0.36 m filled with 1000 mL quality soybean oil were used as the burning sources. Three typical fire scenarios with two, four and six burning sources were selected for the numerical study. Numerical experiments were then carried out for justifying the measured transient temperature using the CFD tool Fire Dynamics Simulator (FDS). Grid sensitivity, two boundary conditions and the heat release rate emitted by each burning source were investigated. The results in this paper indicated that for simulations on fire scenarios with high heat release rate and high fire temperature under natural ventilation, thermal radiation heat transfer into the wall surface should be included. The distances between the burning sources and the ventilation vent would affect the burning duration.