Objectives Perillae Folium (PF) has been widely used in Korean herbal medicines used for treatment of acute and chronic inflammatory diseases, such as rhinitis, asthma, and enteritis. In this study, to investigate the protective effect of PF on type 1 allergic response, we determined whether PF inhibits early or late allergic responses. Methods The effect of PF was analyzed by ELISA,. RT-PCR and Western blot in RBL-2H3 cells. Levels of ${eta}$-hexosaminidase, interleukin (IL)-4 and TNF-${alpha}$ were measured using enzyme-linked immunosorbent assays (ELISAs). mRNA levels of cytokines and enzymes were analyzed with RT-PCR. Signal transduction was analyzed with Western blot. Results We found that PF suppressed ${eta}$-hexosaminidase release in RBL-2H3 by the IgE-DNP-HSA stimulation. PF also significantly inhibited enzymes level, such as COX-1, COX-2, iNOS, and HDC2, along with reduced cytokine levels, such as IL-2, IL-3, IL-4, IL-6, IL-13, and TNF-${alpha}$ in RBL-2H3. In addition, PF suppressed the phospholyation of ERK1/2, JNK1/2, and $I{kappa}B{alpha}$. Conclusions Our results indicate that PF protects against type 1 allergic response and exert an anti-inflammatory effect through the inhibition of degranulation and expression of cytokines and enzymes via the suppression of signal transduction.