Lectin-conjugated praecoxin A, which has developed as a missile antitumor drug, is the one that has conjugated with wheat germ agglutinin (WGA), a kind of carbohydrate-binding protein (lectin) especially bound to melanoma. Praecoxin A is a kind of tannin extracted and purified from plants. Beside this direct antitumor effect as tannins, we have examined an activation of macrophage by lectin-conjugated praecoxin A. We also confirmed the gene expression of IL-1 $eta$, both in vitro and in vivo. We added 1, 10, 100 $mu extrm{g}$/mι of lectin-conjugated praecoxin A, 10 $mu extrm{g}$/mι of lectin, 10 $mu extrm{g}$/mι of praecoxin A to normal murine macrophage and analyzed the extracted total RNAs by RT-PCR after 4, 8, 12, 24 hours. Our data demonstrated that lectin-conjugated praecoxin A increased IL-1$eta$, mRNA expression in a dose dependent manner. However, the effectiveness of lectin-conjugated praecoxin A was not superior to lectin and praecoxin A.