The 2-amino-l-phenylpropanols 4∼7 were reacted with isothiocyanates to afford the 20 thioureido MAPP derivatives 8a∼11e, which were tested their cytotoxic activity by MTT assay. The cytotoxicity of alkylthioureido compounds were increased and decreased by alkyl chain length from $C_{8}$ to $C_{14}$ and of phenylthioureido compounds showed poor activity. The compounds (8b, 8c, 9b, 9c, l0b, 10c, 11b, 11c) with $C_{10}$ and $C_{12}$ alkyl chains gave stronger activity than reference compound B13. The $IC_{50}$/ of compound 8c was 1.05$mu$M and 3 times stronger activity than B13. The stereochemistry of synthesized compounds affected very little to cytotoxic activity.