Abstract: Ten E1 Nino events for 1951-1986 are analysed through the method of clustering and 2 categories are derived. Category 1 (C1) begins heating west of the equatorial eastern Pacific while Category 2 (C2) right over the equatorial eastern Pacific. The two categories of events are studied by means of anomaly compositing and dual expression of EOF in terms of the temporal and spatial structure and characteristics of the anomalous SSTA in the Pacific accompanying with stages from generation to disintegration. At the stages of generation and development, the disturbance in SST field propagates towards east for C1 and `west for C2. Significant opposite features also exist in the anomalous distribution. At the maturing stage, the propagation reverses to the west in the equatorial area for C1 but changes to the north along the longitude and comes to quasi-stationary state for C2. Opposite features still exist in mid-latitudes but those for anomaly distribution disappear. At the disintegration stage, the propagation of disturbed SST fields does not vary much from the previous stage for C2 while C1 becomes consistent with C2 in this respect and does not differ much from C2 in the asnomaly distribution.