This study has attempted to examine and compare the effects of 2007 financial crisis on inflation in OPEC countries and selected countries of G8, based on a panel data regression model during 2000-2010. It should be noted that the selected countries of G8 group are 5 industrial countries member of this group, including: America, Italy, Britain, France and Japan, that crisis has been seen faster in them than other countries. Growth economic variables (real sector of the economy), oil price and stock price index (i.e. financial market) have been considered as affected shared variables of the financial crisis in both countries group. According to the obtained results, the only affected variable by the crisis in OPEC countries, is oil price which has positive and significant effect on inflation in the above mentioned countries so that one percent increase in oil price lead to about 0.08 percent increase on inflation, on the other hand, according to survey results there is no relationship between output and inflation in OPEC countries, so it reflects weak manufacturing structure sector (real sector of the economy) in these countries .