Earning reports are the primary basis of investment decisions among many individuals and fund managers. Any positive/negative adjustment on quarterly financial report could influence investment strategies, which consequently make significant change on market value. In this paper, we present an empirical study on some selected firms on Tehran Stock exchange by looking the effects of quarterly earning adjustment on firm and market’s return. The proposed study selects all firms whose shares were actively and publicly traded over the period 2006-2011. The study investigates whether there is a meaningful relationship between the content of quarterly earnings report and stock price with/without the presence of control variables. The results have concluded that there are some meaningful relationships between change in earning and market value and return on firm with market value but market value seems to have no relationship with market return changes.