On February 15, 2006，China Ministry of Finance formally promulgated the  Impairment of Assets accounting standard, which forbids the reversal of long-term assets write-off. The promulgation of this new standard provides us an opportunity to research on the problem about reversal of long-term asset write-off. Despite the theoretical viewpoints supporting, we believe the new standard is related to earning management. This paper focus on whether the reversal of long-term asset is the result of earning management. If so, the standard that forbids the reversal after 2007 will make the amount of the reversal in 2005 and 2006 to be greater than that in 2004 significantly. The study shows that, only in 2004, after controlling the economic variables, two motivation variables: allotment tendency and free from special treatment are significantly correlated with the reversal, which demonstrates that the reversal of long-term assets is a result of earning management. However, compared with 2004, the effect of allotment tendency and free from special treatment variables in 2005 and 2006 did not increased, but decreased significantly. The study shows that the standard that forbids the reversal doesn't make the motivation of earning management by the reversal of long-term assets write-off to be confirmed.