Atherosclerosis is a progressive disease characterized by the accumulation of lipids and fibrous elements in the arteries. Monocyter/macrophages are involved in many aspects of the development of atherosclerotic plaques. It is known that the intercellular adhesion molecule-1(ICAM-1) expressed preferentially on endothelial cells of atherosclerotic plaque, promotes local adhesion and transendothelial migration of monocytes, neutrophils, and lymphocytes. Using the human promyelocytic leukemia HL-60 cell line, we investigated the inhibitory effects of methanol extracts of 175 natural plants on ICAM-1/LFA-1 mediated cell adhesion. Eight kinds of methanol extracts of tested plants inhibited PMA-induces homotypic aggregationof HL-60 cells without cytotoxicity at the concentration of $6.25;{mu}g/ml$. They were divided two fractions of $CHCI_3$ and $H_2O$ to use solvent partition. Among them, $CHCI_3$ extract $(1.0;{mu}g/ml)$ of Saururus chinensis and Chloranthus japonicus singificantly inhibited aggregation of HL-60 cells without cytotoxicity, respectively.