To obtain the information on antioxidant activity by harvesting parts and time in Cudrania tricuspidata Bureau, total phenolic contents, flavonoid contents, superoxide dismutase (SOD) like activity and 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging activity of methanol extracts from Cudrania tricuspidata were investigated. Total phenolic contents was the highest in leaf [$30.2{sim}38.8;mg/g$ dry weight (DW)] and followed by root bark, stem bark, fruit, root except bark and stem except bark. Among harvesting time, total phenolic contents of leaf was the highest as $38.1{sim}38.8;mg/g$ DW in May and June, and then decreased to October. Root bark harvested in April and May contained $26.6{sim}27.8;mg/g$ DW total phenolic compounds and total phenolic content fell to a very low values at 1.8 mg/g DW in February. Flavonoid contents was very high in leaf and root bark. Especially, root bark harvested in April had the highest of flavonoid contents as 23.2 mg/g DW. As a result of simple linear regression analysis of total phenolic contents on flavonoid contents according to harvesting parts, it showed a high correlation (p < 0.001) with $0.57{sim}0.97;R^2$ (coefficient of determination). As $RC_{50}$ value, that was, the concentration of sample required for 50% reduction of DPPH absorbance, was $13.7{sim}20.5;{mu}g/mL$ in leaf so DPPH radical scavenging activity was very high. But SOD like activity of $1,000;{mu}g$ extract/mL MeOH was a low value of $0.3{sim}9.2%$ in all samples.