This study was conducted to evaluate the distribution, frequency, sensitization rate, and types of specific allergen in allergic patients. We analyzed allergens of 12,882 allergic patient's serum referred for Medical Laboratory using MAST Allergy Screen Test (Inhalation/food panel) from April, 2010 to March, 2011. Allergen reactivity were not detected in 833/12,882 (6.5%) allergic patients and the other allergic patients had two or more types of allergens of food and inhalant, respectively. In the distribution of the allergen food 73.4% (9,450/12,882 patients) was much higher than the pollen 26.6% (3,432/12,882 patients). The sensitization rate to each allergen showed garlic 26.7%, egg white 21.5% of food allergens, mugwort 24.9%, ragweed short 19.6% of pollen allergens, Candida albicans 10.5%, Alternaria spp. 7.9% of fungus allergens, and showed high sensitized rate to Dermatophagoides farinae 90.2%, Dermatophagoides pteronyssinus 77.8%, house dust 57% of indoor allergens, respectively. The specific allergens of food allergen, fungus allergen, and indoor allergen were more frequent in young child than adult, but pollen allergens were frequent in adult than young child. In seasonal distribution, the food allergen were frequent in summer and autumn, the pollen allergen in autumn, fungus allergen in spring and in winter, and indoor allergen in autumn and in winter. In conclusion, the mite of Dermatophagoides farinae and Dermatophagoides pteronyssinus, and house dust showed the highest sensitization rate in specific allergen of allergic patients. The allergens showed difference feature according to the age, region, and types of allergen.