Drug discovery for the treatment of allergic disease is an important field in human health. Natural plants and medicinal herbs used commercially in Korea were screened for degranulation inhibitory activities of 164 plant species in the RBL-2H3 cell line, and their activities were investigated using the ${eta}$-hexosaminidase release assay; 34 species were active. Lactuca indica var. laciniata had the highest degranulation inhibitory activity, and Plantago asiatica, Cimicifuga heracleifolia, Poncirus trifoliata, Lycopus ramosissimus, Quercus mongolica, Anemarrhena asphodeloides, Eugenia caryophyllata, and Curcuma longa exhibited degranulation inhibitory capacity higher than 50% at $125{mu}g/mL$. One compound was isolated by activity-guided fractionation and isolation from methanol (MeOH) extract of A. asphodeloides, which has not yet been identified as constituent for anti-allergic and atopic effects. The structure of isolated compound was elucidated on the basis of NMR and Mass spectrometric data as nyasol, which was highly effective at very low dose ($70.98{pm}1.57%$ at $50{mu}g/mL$). These results demonstrate that natural products and contained compounds may be useful in the therapy of allergic diseases, such as atopic dermatitis and asthma.