This paper presents the results of a preliminary study on the spatial variation of relationships between Indonesian rainfall and the ENSO phenomenon. It also presents the results of an examination on the spatial variation of the lag correlations between the ENSO and rainfall, with a view to establishing the SOI’s use in seasonal rainfall prediction. A monthly rainfall data set covering the period of 1950-1997 for 33 synoptic stations across the region is used. The Troup SOI for the period of 1949-1997 is utilized to represent the ENSO. The results confirm earlier studies about a close relationship between ENSO and Indonesian rainfall. However, it is found that there is a strong seasonality and regionality in the southern and eastern part of the county. The results also suggest that there is possibility of seasonal rainfall prediction using previous observation of SOI.