Herbs have long been known and used for various therapies. Many excellent cosmetics come from herbs. Clary sage, tea tree, rosemary, cedarwood and lavender have long been known for its classic fragrance. In this study, the effect of aroma essential oils on the hair growth and anti-dandruff ability has been studied using microbial test and in vivo test (semi-clinical test). At first, some volatile ingredients from aroma essential oils were identified using GC/MS and datase software. Antibacterial activity of the oils were assayed against Staphylococcus aureus, Malassezia japonica, and Propionibacterium acnes using halo test and agar slant method. Ketoconazole and ampicillin were used as a positive control. Lavender showed the best antibacterial activity throughout the whole strains. In addition to this in vitro test, semi-clinical demonstration of the effect of aroma essential oils on the growth of hair has been shown in this study. The best combination of the aroma essential oils were a mixture of lavender, clary sage, cedarwood (3:2:1, v/v). The main effects of the oils on scalp were anti-dandruff and anti-itching and hair growth.