Six analogues of lacidipine, (E)-diethyl 4-(2-(3-amino)-3-oxoprop-1-enyl)phenyl-2, 6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylates (compounds 1-6), were synthesized and their antihypertensive effects in spontaneously hypertensive rats were evaluated by ig administration. Amongst the tested compounds, compound 5 exhibited the highest antihypertensive effect. The lasting time and potency of compound 5 showed a dose-dependent manner. The results suggested that N-tert-butyl acrylamide moiety at 2 0 -position of 4-phenyl in the structure of analogues of lacidipine is necessary to keep antihypertensive effects.