Abstract Stable isotopes are a very powerful means in hydrological study of water cycle. In contrast, lack of isotope reference database in Thailand and SE Asia region, which available only irregularly database of IAEA’s Global Network of Isotopes in Precipitation (GNIP), make inapplicable interpretation on very dynamic, seasonal control of local hydrological systems. Recently, high frequency stable isotope database in precipitation are developing by the monitoring network, funded by the Nation Water Database Project, Hydro and Agro Informatics Institute (HAII) during 2013-2016. In this study, data interpretation is based on the selected database from 6 rain stations from Northeastern Thailand, which are located in Nakhon Ratchasima (NMA) Surin (SRN), Khon Kaen (KKN),Ubon Ratchathani (UBN), Nakorn Panom (NPM) and Nong Khai(NKI). The database are including meteorological data (Surface Temperature, RH and Precipitation intensity, daily reported at 7am) and stable isotope ratios (δ2H, δ18O) in daily rainfalls (24h) samples, which were collected by standard rain gages and analyzed by the Cavity Ring-down (CRDS) Isotopic H2O Analyzer based on laser absorption spectroscopy. The results of 33 consecutive months from April 2013 to January 2016 provide new perspective of temporal variation and seasonal offset of stable isotopes in the local precipitation in NE region of Thailand, compared to the local meteoric water line (LMWL) of Bangkok (GNIP 4845500) and Luang Phrabang (GNIP 489300). The unique fingerprints of the stations in northern part (NPM and NKI) and eastern part (UBN) of the region indicate the difference in precipitation sources and strong influence of moisture transportation from the South China Sea comparing the other inland stations (NMA, SRN and KKN). The fingerprints demonstrate as effective tracers to investigate seasonal interaction of the run-off in different watersheds as well as the identification of groundwater (GW) recharge sources and mechanisms in local GW basins. Furthermore, yearly weighted average data (Average Annual Rainfall, AAR) show highly inter-annular variations including abnormally enrichment characteristics between 2014-2015. The observation can be implied the relation on regional climate change including the effect of recent warm phase of the El Niño Southern Oscillation.