Country-specific data for net calorific values and carbon emission factors requires for a higher tier estimate of greenhouse gas emissions in the energy sector. The objective of this study is to develop country-specific net calorific values and carbon emission factors for petroleum energy produced in Korea. Calorific values and carbon contents of the fuels were measured using the oxygen bomb calorimeter method and the CHN elemental analysis method, respectively. Sulfur and hydrogen contents, which were used to calculate the net calorific value, were also measured and then net calorific values and carbon emission factors were determined based on the measurement results. The net calorific values and carbon emission factors determined for the petroleum produced in Korea 2012 and 2013 were compared to those in the 2006 IPCC Guidelines. Most of the values were different compared with the default values of the 2006 IPCC Guidelines although those were placed within their upper and lower limits. Time series analysis results showed inconsistent seasonal variation for the net calorific values and carbon emission factors.