To investigate the hypersusceptibility of Chinese Materia Medica Xiaojin Capsule.Methods:Blank control, positive control, and 10 groups of Chinese medicinal materials were set to fulfill the study. Drugs were orally administered every other day for 3 times. Serum was collected on 15 days after the first administration and used to bring up RBL-2H3 cells. Histamine and β-hexosaminidase were detected for hypersusceptibility evaluation.Results:Histamine release from RBL-2H3 cell of Cochinchina Momordica Seed group was obviously higher than that of blank group (P<005). β-hexosaminidase release by RBL-2H3 cell of artificial musk group, Cochinchina Momordica Seed group, frankincense and myrrh group was higher than that of blank. However, there was no statistical difference between blank and processed products of Cochinchina Momordica Seed, frankincense and myrrh.Conclusion:The sensitized Materia Medica in Xiaojin capsule may be artificial musk, cochinchina momordicae seed, frankincense and myrrh. The appropriate processing methods can be used to reduce the sensitization.