【摘要】In this article,from the definition of economic transaction,the author pointed out the three essential of economic transaction:subject object and medium,therefore define accurately economic transaction.Through the comparison and evaluation of transaction classification between the System of National Accounts of China 1992 and SNA 1993,the author pointed out the advisal scheme of the transaction classification of System of National Accounts of China,then discussed flow of transaction through the graphic method.Transaction account and foundational principle.