The purpose of this study is to develop high-efficiency Diesel injection nozzle, which is able to obtain the spray with high-dispersion and high-penetration. In this paper, the effects of the atomization enhancement nozzle, which the excellent spray characteristics with short breakup length, large spray angle and small Sauter mean diameter were obtained at low injection pressure, on atomization of intermittent spray at high-ambient pressure condition and application to the actual Diesel injector were investigated. As a result, it was cleared that the spray tip penetration of the atomization enhancement nozzle corresponds to a single hole nozzle for a D. I. Diesel injector, spread of the spray becomes large compared with a single hole nozzle and high-dispersion spray was obtained at the intermittent injection under high-ambient pressure.