Abstract: A three-dimensional complex flow field can be determined by measuring the velocity at each given point twice at two different angles with the aid of a DISA two-dimensional LDA system. The complex flow pattern of a vaporizing tube model combustor including recirculating zones has been identified clearly. The turbulence distribution has also been obtained. It has been shown that the flow field was very complex. The section area of the vortex in the vertical plane passing through the center-line of a vaporizing tube occupied about 55% of the cross section area of the whole primary zone. The average rotating speed of the vortex has been estimated about 2700 rpm. The frequency shifting of the LDA system must be always employed in combustor flow field measurement not only for determining flow directions reliably but also for obtaining the average velocity values correctly.