The paper introduces the optimization and implementation of chemotherapy injection process for out-patients based on HIS system. Taking Tumor Hospital Affiliated to Sun Yat-sen University as an example,it points out the existing problems in the progress and expounds the detail design and implementation of optimized chemotherapy injection process for out-patients from the following aspects: e-books of chemotherapy program for out-patient doctor station, injection pricing reservation, automatic pharmacy dispensing, dispensing and injection confirmation. Electronicalization and informatization of the whole process can be achieved by using HIS system.