Effects of gamma irradiation on color characteristic and biological activities of ethanol extract of Lonicera japonica irradiated at 0, 10, 20, and 30 kGy were investigated. Hunter color $L^*$- and $a^*$-value increased by irradiation in a dose-dependent manner, resulting in lighter color than the nonirradiated, whereas Hunter color $b^*$-value decreased with increasing irradiation dosage (p <0.05). The L. japonica extract showed inhibition effects against tyrosinase, xanthine oxidase, and nitrite-scavenging ability. Tyrosinase inhibition effect of L. japonica was higher in the gamma-irradiated sample than in the nonirradiated sample, and the effect was increased by increasing irradiation dosages. The L. japonica extracts had a higher inhibitory effect against xanthine oxidase, and the effect was not greatly changed by irradiation. Nitrite-scavenging activity was the highest in L. japonica extract at pH 1.2. Overall, the gamma irradiation may not greatly influence the xanthine oxidase inhibition effect and nitrite-scavenging ability of the L. japonica extract, except for the tyrosinase inhibition effect when irradiated up to 30 kGy.