Although there is the relationship between rainfall variability over the Southeast Asia and ENSO (Juneng and Tangang, 2005), it obviously related to ENSO during summer season (Chen and Yoon, 2000). During winter season, the principal spatial pattern of rainfall over the Southeast Asia shows large variation over the Borneo (Juneng and Tangang, 2005). The pattern does not capture the principal characteristic of rainfall over the Indochina due to the rainfall over the Borneo accounts more variation of rainfall than that in the Indochina during the winter season. Nevertheless, there is the possible relation among the winter monsoon governing the Indochina, rainfall over the region during winter season, and the forcing from