;Abstract For investors compare companies financial report high quality accounting stan- dard is require. Target of IFRS is to develop global accepted high quality accounting standard. Now many countries are using IFRS in the world. Prior researches are rep- orted that IFRS permits flexibilities on accounting and under IFRS these flexibilities may be used to increase and inflate earnings. The purpose of this thesis is to study after switch from U.S.GAAP to IFRS which factors cause increase and inflate earnings under IFRS. This paper referenced from various kinds of accounting books and IFRS related books, also referenced from various kinds of journals、theses、internet ar- ticles、articles from accounting firm and U.S.Securities and Exchange Commission、 international accounting standards、ebooks and dictionaries that are related to this study. This thesis is descriptive type of research, therefore there have no empirical a- nalysis but for explain and prove some of the calculation include in this study. In this research collected detail of some factors that are difference between U.S. GAAP and IFRS ,such as reversal of impairment loss、capitalization of R&D、LIFO change to FIFO and earnings management under IFRS ,also show that these Factors how to related with increase and inflate earnings under IFRS.
