Objective To elucidate the relationship and development of food safety and its hygiene. Method From the definition of food, the relevant definitions of food hygiene with food safety were compared, the four relationships for hygiene and safety, hygiene but not safety, safety but not hygiene, and neither hygiene nor safety were analyzed. Results Both safety and hygiene may be properties of food, the concepts of food safety and food hygiene may be difference. They were same parts as well as different parts. The aspects on the safety and hygiene could not be said that it was important or not important between the food safety and food hygiene. Conclusion Food safety may not be advanced phase of food hygiene and both would be very important.