Abstract: Agricultural product safety problems occur frequently and this makes people nervous.So it is important to strengthen the management on quality and safety of agricultural products.From the perspective of supply chain of agricultural products, the paper presented a quality and safety traceability system.Firstly, the characteristics of agricultural product supply chain and system requirements were analyzed.The system adopted the architecture of multi-layer distributed system.The whole system could be divided into 6 layers including user layer, interface layer, application layer, support service layer, data layer and equipment layer.Secondly, according to the actual needs of the system, the paper illustrated business process of agricultural product supply chain.Based on the idea of the top level design in system engineering, the modular design method was adopted to divide the system main functional modules.The system could be divided into 5 subsystems which included register, production, enterprise management, government supervision and traceability subsystem.Database was the basic part of the system.On the basis of the principle of consistency, integrity, security and scalability, each table in the database was standardized in design.The QR(quick response) code was the most important part in the whole system.In order to expound the process that QR code was generated, a lot of work needed to be done.Under the guidance of HACCP(hazard analysis and critical control point) management system, and after analysis on possible dangers of the agricultural product supply chain, the paper described key factors affecting the quality and safety of agricultural products, and then encoding objects were identified.These encoding objects referred to the origin of agricultural products, product registration number, production batch and harvest batch.Based on certain rules about agricultural product encoding, each encoding object corresponded to a series of numbers.After the digital information was transformed into graphic information, the QR code came out.Each user could scan QR code through a mobile phone or computer to obtain detailed information on agricultural products.System implementation used the popular B/S architecture, took the HighCharts and jQuery as front frames; and with the help of the AJAX(asynchronous JavaScript and XML) asynchronous interaction and JSON(JavaScript object notation) data transmission technologies, this system could be successfully realized.Finally, the article showed the interfaces of some functional modules to demonstrate the effectiveness of the system.The system realizes the agricultural products whole supply chain of the entire process of tracking and tracing which was from the planting, harvesting and processing to the sales.The government management department could realize the on-line office work and improve the supervision efficiency through this system.Agricultural product production and management enterprises could standardize the production operation process, and improve the production management efficiency.Consumers could obtain product information through computers, mobile phones and so forth.If there was a problem of agricultural product quality and safety, consumers could protect their legitimate rights through legal channels.Development of agricultural products quality and safety traceability system was a cooperative project which was designed by Hefei University of Technology and Jiangyin Inspection and Testing Center of Agricultural Products Quality and Security.After expert evaluation, the system has passed the project acceptance.