In order to move to the fair value based financial reporting from historical cost based, impairment testing, is a new cautious approach. Information reported in the financial statements if the Impairment of assets not reported, will not be useful for decision making by users. The present study aims to provide a theoretical survey of the reasons and importance of reporting the Asset Impairment in terms of agency theory, signaling theory andlegitimacy theory. Also the market evidences of the consequences of reporting the Assets Impairment from view of the Value relevance, Timely reporting, audit fees, earning management, future returns and Analyst forecast accuracy is examined. What is inferred from the results, reporting a decrease in the value of assets would be admitted to the exercise of management's judgment in manipulation of activities and real events, as well as from view the motivational impact of accounting standards and agency problems, due to the flexibility that exists in this standard, Can be cause sufficient incentives for management to deal with complex and unexpected situations.