This study is to investigate the effect of pressure on the behavior of an impinging spray. We obtained the frozen images which were scattered by Nd-Y AG laser light (pulse width : 7 ns) with synchronizer manufactured for this study. The penetration length, spray thickness of the spray, growth rate, and ratio of growth rate were estimated from the frozen images. The effect of ambient pressure on the penetration was larger than that of injection pressure. A lower injection pressure or a higher ambient pressure was required for good spatial distribution of impinging spray. The ambient pressure had greater effect on the growth behavior of penetration. The pressure ratio had an effect on the penetration growth rate. A higher pressure ratio resulted in faster growth of penetration length. The thickness growth rate depended on the injection pressure and the ambient pressure respectively. The behavior characteristics of impinging spray was changed by the momentum change related to the disintegration of droplets when the injection of fuel was finished.