Measurement of (1-->3)-beta-D-glucan for invasive fungal infection is used practically in Japan. The problem of false positive results due to the frequent occurrence of non-specific reaction in alkaline treatment, chromogenic automated kinetic assay to measure (1-->3)-beta-D-glucan had been recognized in Japan. But this important problem was resolved in July 2005 by improvement made in the pretreatment reagent in a (1-->3)-beta-D-glucan measurement kit. In this manuscript, we describe the process of improvement of this kit and its clinical usefulness.