Many studies have explored suppression of aflatoxin produced by Aspergillus Genus. On the other hand, this study examined the inhibitory effect of the culture broth extract (CE) of A. tamarii obtained from dead silkworm on nitric oxide (NO) production and its antioxidative activity. The culture broth was extracted with EtOAc, dried, and then used in this experiment. As a result, CE did not show cytotoxicity on RAW 264.7 cells at any concentration. Moreover, CE suppressed lipopolysaccharide (LPS)-induced NO production of RAW 264.7 cells in a dose-dependent manner. The total phenol content according to the Folin-Dennis method, the antioxidative activity by DPPH, and the nitrate radical scavenging capacity of CE were increased in a dose-dependent manner. Thus, many of the phenolic compounds were considered to represent the antioxidative activity.