Income recognition principle under IFRS and GAAP has changed into convergence in the last few years.With a demand of converting to IFRS, Chinese accounting standards have also obtained development in income recognition.All income recognition principles under the three different accounting system contain core element of 5-step model for income recognition.On the other hand, they all maintain certain difference as the external environments vary from place to place.For IFRS, which is principle based, the new IFRS 15 prescribes more detailed methods to deal with construction contract, variable consideration and contract amendments.For GAAP part, income recognition steps with special requirements and difference with IFRS 15 is illustrated in detail.For Chinese accounting standards, with an unmatured market, they maintain a relatively flexible requirement with potential problems.This essay demonstrates major differences among the three principles towards income recognition, further exploring disadvantages of current principles.