The source of clinical evidence in drug development has been limited to be generated from clinical trials for many years. However, the evidence generation should be extended to Real World Data (RWD), which will play a key role anywhere. The ICH GCP renovation recommends selecting from a variety of clinical trial designs and data sources choices where innovative new drugs will be provided to patients as an earlier approval of the new drug application. In the early-stage approval system of the Ministry of Health of Labor and Welfare and the revision of GPSP in Japan, it is clearly stated that medical databases and patients' registry will be available. In this manuscript, we summarize the following cases of the utilizing RWD in drug development； (1) submitting data for a new drug application, (2) planning of clinical trials and patients' recruitment for clinical trials, (3) collecting clinical trial data using Electronic Health Record as data source, (4) assessing clinical outcomes and diagnosis, (5) developing strategies of drug development, drug pricing and access. Although there are many challenges in each application and the improvement in the infrastructure and regulatory environment is desired, we hope the progress of RWD use in the practice of drug development without waiting for that.