Majority of asthma and atopic dermatitis are known to be spontaneously sensitive to house dust mite allergen. Control of house dust mite populations has been principally achieved by using chemical insecticides. But the risk to human health would be a potential problem. Moreover, house dust mite remain as allergens even after death. So, It is more effective method keeping the house dust mites away than killing them. The use of plant-derived repellents has been considered as a promising alternative to chemical repellents. Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. It has insect repellent properties and is an active ingredient in some commercial mosquito repellents. These studies were carried out to investigate repellent effects of Eucalyptus oil against house dust mites and compare lemongrass oil. Eucalyptus oil and lemongrass oil were exposed at different doses (0.2, 0.1, 0.05, 0.025, 0.0125, $0.00625{mu}l/cm^2$) and different times (1, 3, 6 hours) on house dust mites. The most effective dose of Eucalyptus and lemongrass oils against house dust mites was $0.1{mu}l/cm^2$ and $0.025{mu}l/cm^2$. Each repellent effect(%) in most effective dose was 90.3% (Eucalyptus) and 80.8% (lemongrass).