Different kinds of Lavandula species have been used traditionally throughout history.Lavandula extract (fragment oils of its flowers) is used in blood clotting treatment, neurological diseases and rheumatoid. In this research, the effects of suppress the immunosystem of the BABL/c mice, which were infected by cutaneous leishmaniasis, were studied. Sufficient twigs of Lavender flowers were minced and put in ehanol 80%. They were placed into the stirrer with magnets in room temperature for 24 hours, then separated. This compound was, first, sterilized and prepared as topica with concentration of 40, 60 and 80%. It was refrigerated until used. In the lab, 40 BABL/c mice were infected with the parasite Leishmania (L) major [MRHO/IR/75/ER].They were divided into four control groups and a group that received 40, 60, and 80% concentration of the Lavandula extract. As soon as the leishmania lesion appeared, Lavandula extract was applied every two days. As well, the foot and size of the lesion were measured, the weight was also taken in all mice in the four groups by using ale and coliss (Mettler, Switzerland) every week. The mean of the measurement and weight of the mice that were received 40 and 60% of the Lavandula extract showed significant difference comparing with the mean of the weight of the mice in control group, but the mean of weight in the mice received 80% of the Lavandula extract did not show significant difference with the weight of mice in control group (P>0.05). The mean of lesion size of the mice that received 40 & 60 of Lavandula extract showed significant difference with the lesion size in controls groups (P=0.000), but the lesion size of the mice receiving 80 of the Lavandula extract did not show significant difference with those mice in control groups (P>0.05). Using of the Lavandula extract, the process of weight decrease of the animal increase, and as much as the concentration of the Lavandula extract increase, the weight of the animal decrease. However, increasing the concentration more than 80%, showed no remarkable increase in weight of the animal. Totaly, in comparing to control group, the process of mortality was increased with weight decreasing and lesion size increasing, in mice receiving Lavandula extract. In addition, the death of the mice receiving Lavandula extract was more than the mice in control groups and their lesion size was wider with severe necrosis.