Based on the monitoring data for tropical atmospheric and oceanic features,the special climate background for the occurrence of 1994/1995 ENSO event was diagnostically analyzed.Meanwhile,the process and characteristics for the o)nset and development of the ENSO event and its impacts on the world weather and climare conditions were also discussed. These resllts provided detail observed and analyzed facts for the researches on tropical ocean-atmosphere interaction.and also the theory,modeling and prediction for ENSO event.