-The effect of blue primary color on image quality was studied. We used the KANSEI evaluation method, and for experiments, we used Semantic Differential method. First, four different blue primaries of 430, 450, 470, and 480 nm with full brightness of L max equal 60 cd/m 2 were tested.The same experiment was performed for 450, 470, and 480 nm at L max of 170 cd/m 2 . The results for the four primaries show that 450-and 470-nm blue primaries are the best. Then 430 nm was next, and 480-nm blue primary shows the worst performance. In the tests of three primaries, the 470 nm shows the highest scores for bluish test images. Results are compared with color naming data in the entire chromaticity diagram.