Abstract: Electron beam is unsubstitutable to the therapy of tumors/cancers at body surface or superficial layer because of the limited irradiation range of high-energy electron beam that may avoid efficiently the irradiation into the deep tissue behind target area. The calculation of physical parameters included in the Hogstrom pencil-beam dose calculation algorithm is thus studied further to explore the basic principles of them and how to calculate them in accordance to practical clinical conditions. The results show that the Hogstrom algorithm is available to solve the problem of calculating electron beam dose.