This study presents the eddy covariance measurement results of energy fluxes covering one year data (2010) in dry dipterocrap forest in western Thailand. The study site was located within the 88.9 ha-dry dipterocarp forest inside the campus of King Mongkut's University of Technology Thonburi (KMUTT), Ratchaburi Province (13 o 35 ' 13.3 '' N, 99 o 30 ' 3.9 '' E). The analysis is focused on the energy budgets during the contrasting climate anomalies; long dry period of 2010 (5 months) during January-May 2010, and the late coming and long lasting raining period of 2010. We hypothesized that such unusual long dry period could affect the dynamics of energy balance in tropical seasonal forest ecosystems. This is one of aspects that could help us to improve our understanding of carbon cycling (e.g. photosynthesis and respiration processes) in dry dipterocarp forest during extreme climate phenomena. The components of energy budget reported are sensible heat, latent heat and soil heat flux. We found that total net radiation (Rn) in 2010 (11.21 MJ/m 2 /day) was similar to 2009 (11.29 MJ/m 2 /day). However, sensible heat flux (H), latent heat flux (LE) and soi l heat flux (Gs) with stored in biomass (Sb) were different during dry and wet season. H was very high during dry seaso n especially in April then decreased to very low value during rainy season. Thus in dry season most of energy was used for burning the air (71% or 7.62 MJ/m 2 /day), the rest was for evaporating water (14% or 1.54 MJ/m 2 /day) and for stori ng in soil and biomass (15% or 1.59 MJ/m 2 /day) respectively. This was opposite to the pattern of LE, which was high du ring wet season especially in September and then was low during dry season. Thus in wet season most of energy was us ed for evaporating water (69% or 7.85 MJ/m 2 /day), storing in soil and biomass (20% or 2.35 MJ/m 2 /day) and for burni ng the air (11% or 1.34 MJ/m 2 /day) respectively. High LE was consistent with the high net carbon exchange during wet season in the second haft of 2010 (net carbon sink of 13.14 ton CO 2 /ha/y or 3.58 ton C/ha/y). It was concluded that long dry period did not affect to total energy budget but effectively altered its components, i.e. sensible heat and latent heat a nd this is related to the carbon exchange of dry dipterocarp forest.