In 2002, we reported that sweetpotato leaves contained six caffeic acid derivatives, namely, caffeic (CA), chlorogenic (5-O-caffeoylquinic acid, ChA), 3,4-di-O-caffeoylquinic (3,4-diCQA), 3,5-di-O-caffeoylquinic (3,5-diCQA), 4,5-di-O-caffeoylquinic (4,5-diCQA), and 3,4,5-tri-O-caffeoylquinic (3,4,5-triCQA) acids, which are known to have many physiological functions. A new sweetpotato cultivar ‘Suioh’ was developed for use of its tops as an edible green by KONARC. It is important to analyze the caffeic acid derivatives efficiently with high-performance liquid chromatography (HPLC) in order to continue developing or selecting new cultivars with higher contents of these compounds in their tops. For this purpose, a short column (4.6 i.d. × 75 mm) packed with small ODS particles (3 μm) was used without replacing the conventional HPLC apparatus and the time for one analysis per sample was decreased to 26 min, from 90 min, which was the analysis time reported in 2002. With the new HPLC conditions, we could quantify the six caffeic acid derivatives in lyophilized leaf samples from 529 sweetpotato cultivars, which compose approximately one-third of the cultivars maintained at KONARC.