Abstract. This research is aimed to estimate energy consumption and the greenhouse gases emission from olefins production process in Thailand and to analysis its correlation between energy intensity and carbon intensity. The results of five olefin case study plants showed that direct energy use of olefins production was about 87% of total energy consumption. The greatest amount of energy demand was supplied for fuel combustion in manufacturing processes. The olefin plants using gas feedstock could operate with less amount of energy consumed as the average energy intensity (EI) of 23.88 GJ/ton of olefin produced, whereas plants of olefin produced from steam cracking of liquid feedstock had the average EI of 33.21 GJ/ton of olefin produced. Greenhouse gas emission from olefin plants using gas feedstock were consistent with the result of EI. The carbon intensity (CI) from olefin plants using gas feedstock (0.98 tCO2-eq./ton of olefin produced) was lower than the plants using liquid feedstock (2.01 tCO2-eq./ton of olefin produced). The T-test function used to reflect the correlation between EI and CI emphasized that the carbon intensity was significantly correlated with the intensity of energy (r = 0.9564 and p = 0.05).