Interactions between precipitable water (PW) and sea surface temperature (SST) over the Equatorial Pacific are investigated using satellite observations and model reanalysis for the period from 1988 to 1995. Time series of area averaged total precipitable water and SST and their anomalies over the so-called Nino3 Box (150°W-90°W, 5°S-5°N) and the counter regions over the northern and southern hemispheres, (i.e., over the same longitude width and from 0° to 10°N, and from 0° to 10°S) were analyzed. The interactions between these two climate parameters over the tropical Pacific and their relationships to global mean total precipitable water vapor and precipitation will be examined using statistical analysis technique. The preliminary results will be discussed and presented in the conference and paper