To discover novel nitrogen mustards, the reported mustard pharmacophore was combined with natural pentacyclic triterpenes, which are characterized with pharmacological and structural diversity. Thus, six conjugates were synthesized with 1,2,3-triazole linking N,N-bis (2-chloroethyl)-1,4-phenylenediamine and oleanolic acid, ursolic acid, or glycyrrhetinic acid, and their biological activity was evaluated against tumor cell lines HeLa, BGC-823, BEL-7404, and NCI-H460 using the MTT assay. As a result, these conjugates showed some selective cytotoxicity to NCI-H460, though all their activity potency was moderate or weak in the four cell lines. K E Y W O R D S N,N-bis (2-chloroethyl)-1,4-phenylenediamine, nitrogen mustards, pentacyclic triterpenes Chun-Mei Liu and Xiao-Yan Tian contributed equally to this study.