This paper analyzes the process from gestation to maturity of fast electronics, describes the three-level relations formed in the development of fast electronics, i.e. that of application, technique and theory, and summarizes in brief the progresses in simulation of electromagnetic fields, high-speed parallel sampling, and research of time jitter. Application results of fast electronics in national economy and national major science projects are also introduced.fast electronics, simulation of electromagnetic fields, parallel sampling, jitter, time interval measurement Citation: