PROFINET is the open standard for industrial Ethernet. PROFINET Component Based Automation(CBA) technology makes the communication between distributed automation systems easier and more efficient by providing standardized automation components. This study introduced the theory and model of PROFINET CBA. PROFINET CBA components based on PROFINET Runtime Source were developed and a real-time communication system was implemented. PROFINET CBA technology can be applied in constructing a distributed automation communication system.