A life cycle assessment(LCA) is increasing its applicability as a powerful tool for an environmental burdens analysis. In this study, some cases are compared in terms of analysis procedures and results obtained with LCAs for evaluating power generation technologies in Korea. For the comparison, 3 power generation technologies are selected because they produces almost 90% of 2003 total electricity generation in Korea. It is shown that the range of evaluation values amounts to maximally the order of about 105, which is rather large discrepancy than the level of 101 in comparison with foreign studies. The difference seems to be due to the simplicity of modeling used in each case study. It is proposed that this large discrepancy should be obviously clarified to improve their reliability in that electricity is a essentialness for all industries and the capacity of LCA of national-level electricity affects the results of LCA for the other sectors.