The spray microscopic characteristics in cross flow were experimentally investigated by using a single-hole gasoline direct injection injector and an optical wind tunnel. A particle image analysis system with double-pulse laser illumination was employed for droplet detecting at a series of measurement points in both the windward and leeward regions. The droplet morphology, statistics, and breakup process are sequentially examined. Large amounts of ligaments and large droplets were detected at the windward region while dispersed small droplets were observed at the leeward region. Qualitative analysis of the droplet images shows that the undesired large ligaments and droplets are less in number and smaller in size for the higher cross-flow velocity condition. Quantitative analysis of local droplet size distributions shows that smaller droplets get more affected by the airflow and hence penetrate farther in the radial direction, leading to an expanded dilute spray region. It is indicated that cross flow improves the atomization quality. Along the airflow direction, the droplet Sauter mean diameter is decreased, the horizontal mean velocity is increased, while fluctuations caused by the vortexes were also detected in some special locations. Statistical analysis of droplet Weber number shows that the droplet breakup is relatively active in the upstream region and gradually weakened along the axial direction and also the airflow direction. In addition, the droplet vibrational breakup, bag breakup, and sheet stripping breakup were identified in the spray.