Currently, there are many different wave energy converters. Their levelized cost of energy of extracting wave energy are still much higher than other matured renewables. The findings of the review show that disagreements of levelized cost of energy are due to the different cost constitutions and their measuring method of capital expenditure and operational expenditure. In the assumed scenario of case study with structure of cost, one-step investment program of half-discounted model is superior to the multi-step investment of discount model. Thus, investment form should be considered into the variables of levelized cost of energy