Ochnaflavone is a medicinal herbal product isolated from Lonicera japonica that inhibits cyclooxygenase-2 (COX-2) dependent phases of prostaglandin $D_2(PGD_2)$ generation in bone marrow-derived mast cells (BMMC) in a concentration-dependent manner with $IC_{50}$ values of $0.6{mu}M$. Western blotting probed with specific anti-COX-2 antibodies showed that the decrease in quantity of the $PGD_2$ product was accompanied by a decrease in the COX-2 protein level. In addition, this compound consistently inhibited the production of leukotriene $C_4 (LTC_4)$ in a dose dependent manner, with an $IC_{50}$ value of $6.56 {mu}M$. These results demonstrate that ochnaflavone has a dual cyclooxygenase-2/5-lipoxygenase inhibitory activity. Furthermore, this compound strongly inhibited degranulation reaction in a dose dependent manner, with an $IC_{50}$ value of $3.01{mu}M$. Therefore, this compound might provide a basis for novel anti-inflammatory drugs.