The spray formation for a heavy duty diesel engine is calculated and compared with the direct and Schlieren photography. The calculation is performed by three dimensional numerical analysis based on KIVA computer program. The discrete particle technique is used for the spray modeling.The drag force of the spray droplet in the calculation is adjusted to have a same penetration with the experiment. The calculations are performed to investigate the influence of the evaporation, combustion, and coalesence for the development of the spray. The results of the calculation are visualized using three dimensional iso-surface to compare with the photograph. The comparison shows that the calculated reaults gives the similar feature on the distribution of each property with the experiment.