Numerous studies were undertaken for scientific support of the APN-funded project of the network system for monitoring and predicting ENSO events and the sea temperature structure of the warm pool in the western Pacific. This paper is a brief summary of scientific highlights derived from this project which include: (1) Development of some new indices for monitoring ENSO events and sea temperatures and associated convective activity over the warm pool in the western Pacific. (2) Development of a number of dynamic and statistical models for prediction of ENSO events on the basis of which multi-model ensemble predictions for both dynamical and statistical models are made. Verfication of predictive skills shows good model performance. (3) A proposal for an air-sea interactive conceptual model applicable to predicting sea temperatures over the warm pool by using the subsurface currents and temperature dataset from the TOGA-TAO array. Observational evidence is presented to reveal the formation mechanism and eastward propagation features of subsurface current anomalies driven by the strong westerly wind anomalies over the warm pool in the western Pacific Ocean.