The light-emitting diodes (LEDs) have become popular, and it is necessary to evaluate the color qualities of LED lighting. Color discrimination is one of the important aspects of color qualities at museums, stores and so on. In this study, we compared two types of 100-hue test under LED and conventional lightings to examine the influence of test samples, especially saturation on the evaluation of color discrimination. One was ND-100 (average = 13.43), the other was Farnsworth-Munsell 100-Hue Test (average = 25.67). The colors of test lights were daylight, neutral white, and incandescent color. Observers performed two types of 100-hue test under all test lights. Results show that the trend of color discrimination in ND-100 and Farnsworth-Munsell 100hue test are similar, and there is a little difference between LED and conventional lights in general. INTRODUCTION Light-emitting diodes (LEDs) lighting has become popular because of their advantages such as energy saving, long life. Conventional light sources are getting replaced by LED light sources and we often see LED light sources at stores, at home and at museums. As the color appearance of objects is influenced by light sources, it is necessary to evaluate the color quality of LED lighting. One of the important aspects of lighting quality would be color discrimination especially for situations that small color difference is critical, such as museums, stores, offices dealing with color management. There are some studies on discrimination task under various lightings, but they do not focus on difference between conventional lights and LED lights. Although some studies used a 100-hue test to evaluate the light sources [1][2], they did not examine the effect of saturation on the performance. In this study, we investigate the difference of color discrimination between conventional lights and LED lights and examine the influences of test colors with low and high saturation on discrimination performances by comparing two types of 100-hue test. EXPERIMENT Experimental setup A viewing box covered with medium gray (approximately equal to Munsell N6.5) matt paper was used for the experiment. Its size was 60 cm (length) × 89 cm (wide) × 40 cm (height). It was illuminated by one of test lamps and a 100-hue test was placed on the center of its bottom. Horizontal illuminance at the position of a 100-hue test was approximately set to 1000 lx (±10 %). O A 15