Trichosanthin (TCS) whose molecular weight is 26000.0 (hereafter called injectable TCS) is a type I ribosome-inactivating protein possessing various pharmacological properties including anticancer effect, inducing mid-term abortion, immunomodulation and anti-HIV activities. Especially, its anticancer effect is more important. In clinic, injectable TCS has been used to treat chorioblastoma as an effective anticancer agent highly specific to choriocarcinoma cells. But injectable TCS also showed immunogenicity and was prone to cause allergic reaction, the application in clinic is restricted thereby. In this study, we initially purified new components of trichosanthin from fresh root tubers of Trichosanthes kirilowii Maxim of wild type and artificial planting type respectively. Then we determined their molecular weights and N-terminal amino acid sequences. Finally, we compared the allergic reaction of guinea pigs to new component of trichosanthin and injectable TCS. In conclusion, the new component of trichosanthin can be used as a new drug with wide spectrum anticancer effect and without allergic reaction