Imperatorin, a biologically active furanocoumarin from the roots of Angelica dahurica (Umbelliferae), was mutagenic and induced transformation of mouse fibroblast cell lines, whereas it provided inhibiting effects on mutagenesis and carcinogenesis induced by various carcinogens. Furthermore, it has been suggested that imperatorin may have potential anticarcinogenic effects when administered orally in the diet. In addition to its anticarcinogenic properties, imperatorin has been shown to possess anticancer activities. We investigated the macro scale gene expression analysis on the HL-60 cells treated with imperatorin. Imperatorin (10μM) were used to treat the cells for 6h, 12h, 24h, 48h, and 72h. In a human cDNAchip study of 10,000 genes evaluated 6, 12, 24, 48, 72 hours after treated with imperatorin in HL-60 cells. Hierarchical cluster against the genes which showed expression changes by more than 2 fold. Three hundred eighty six genes were grouped into 6 clusters by a hierarchical clustering algorithm. Pathway analysis using gene microarray pathway prof Her that is a computer application designed to visualize gene expression data on screen representing biological pathways and groupings of genes.