Serological surrogate tests for invasive fungal infection have been used practically in Japan. The Aspergillus galactomannan antigen detection kit by enzyme linked immunosorbent assay is the most reliable test for making a diagnosis of invasive aspergillosis. But in recent years, occurrences of false positive and negative results have also been reported by several investigators. Therefore, evaluation of the results of this assay should be done carefully in the clinical stage. Moreover, some other methods to detect the Aspergillus antigen or anti Aspergillus antibody in serum have also been reported. The problem of false positive results due to the frequent occurrence of non-specific reaction in the alkaline treatment, chromogenic automated kinetic assay to measure (1-->3)-beta-D-glucan had been noticed in Japan. But this important problem was resolved by improvement of the pretreatment reagent in this kit in July 2005. In this manuscript, I describe recent trends of serological surrogate tests for Aspergillus infection and the process of improvement of the (1-->3)-beta-D-glucan measurement kit.