interpretation of gross profit ratio Any transaction can be seen as a contract between the two parties. The so-called transaction cost can be seen as the cost of the transaction contract. According to Mr Coase and others, a type of transaction costs arise from the accidental factors that occur when a deal is signed. These incidental factors may not be written into the contract due to the fact that they could not be foreseen in advance, or although they could be foreseen, they could not be written into the contract due to too many factors. Another type of transaction costs is the signing of contracts and the cost of monitoring and enforcing contracts. Investors are confused and lost on the way forward, the confusion and bewilderment itself will keeps everyone to learn, so investors are eager to learn has been exist, is the power of the instinct of the profit will lead us to learn. It is not easy to learn the key question is: futures, its difficulty may not be less than the difficulty of the transaction, this kind of difficult to make a lot of people were forced to study only a period of time, that then is in a state of flow for a long time, but it is difficult to further more in-depth study. Mooney and si prowse in its around the main accounting principles for enterprises ", not only emphasize to determine profits in a timely manner, and emphasizes the necessary through division operating earnings, the gains and the impact of price changes, to improve the comparability of financial statements and understandability.