The present study investigated the physiological functions of sweetpotato leaves and as a resource for products with these functions. The polyphenolic compositions and the potential chemo-preventative properties such as radical scavenging activity and antimutagenicity of leaf extracts were compared in six selected sweetpotato (Ipomoea batatas L.) genotypes. The total phenolic content ranged from 12.18 to 16.17 g/100 g Dry Weight (DW). The Radical Scavenging Activity (RSA) ranged from 1.09 to 1.85 μmol Trolox mg-1. In the case of RSA, the cultivar V-5 showed highest activity (1.85 μmole Trolox equivalence mg-1 DM) and V-3 was the lowest (1.09 μmol Trolox equivalence mg-1 DM). The significant positive correlation between the radical scavenging activity and the level of total phenolic (r = 0.62; n = 90; p<0.01) suggests that phenolic compounds are important antioxidant components of sweet potato leaves. The antimutagenicity of the six sweetpotato genotypes studied ranges from 77 to 96% inhibition. The polyphenolic compositions of sweetpotato leaves were identified by using the Reverse Phase-High Performance Liquid Chromatography (RP-HPLC). All the RP-HPLC profiles of the genotypes tested showed peaks at the same retention times but peak areas of individual phenolic compounds differed. Six caffeoylquinic acid derivatives of sweetpotato leaves were identified and quantified. They include: caffeic acid, chlorogenic acid, 4,5-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, 3,4-di-O-caffeoylquinic acid and 3,4,5-tri-O-caffeoylquinic acid. The caffeoylquinic acid derivatives showed higher DPPH-radical scavenging activity (%) and antimutagenicity by effectively inhibiting the reverse mutation induced by Trp-P-1 on Salmonella typhimurium TA 98. Thus, these phenolic components have potential value as chemo-preventative materials for human health.