It is important to write a data physically into a smart card with integrity. The EEPROM buffer design there is relationship which is close with a Smart Card life time. And, it approaches a file and against at the time when it controls a data the dependence degree is high very. Rankle and Effing suggested atomic operations which are based on the idea that when data is stored in an EEPROM, data must never be written only partially. Efficient designs and implementations of a writing process are suggested with atomic operation in two aspects, capability and processing time. In the aspects of the capability, a new cyclic structure of a buffer extends 8 times an EEPROM lifetime in average. A new cyclic record structure reduces about 30% of processing time to an EEPROM for backup. Suggested methods can be applied to design of T-money that is the traffic payment application of Seoul City. It is implemented to the S3C89V8 memory chip of Samsung Electronics.