Regionalization of homogeneous climate zones was done using Fuzzy C -Means method. Besides, correlations between dry/wet variations and El Ni?o/Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Indian Ocean Dipole (IOD) and Pacific Decadal Oscillation (PDO) in annual and seasonal time scales were analyzed across the Pearl River Basin using Pearson correlation and moving correlation analysis. Furthermore, stability and diversity of influences of ENSO, NAO, IOD and PDO on annual and seasonal dry/wet variations were also investigated. Moreover, influences of warm and cold phases of climate indices on SPI-based dry and wet regimes in 6-month time scale were studied and the results indicate that: (1) IOD, NAO and ENSO are the main driving factors behind annual, wet and dry seasonal precipitation changes respectively. And the influences of them on the precipitation in the same year and next year are opposite; (2) The moving correlation between precipitation in different time scales and corresponding climate indices (annual precipitation and IOD, wet seasonal precipitation and NAO, dry seasonal precipitation and ENSO) tend to be in strong correlation with good stability; (3) The influences of climate indices on precipitation in different time scales are not uniform in spatial distribution; (4) There are significant differences between influences of warm/cold episodes of climate indices on dry and wet regimes in the Pearl River Basin. Overall, the probability of wet periods occurring in the warm phase of climate indices is greater and more uniformly distributed than that in the cold phase over the Pearl River Basin.