Among energy carriers, the role of oil is more remarkable in economic development of developed and developing countries. But the fluctuations in oil price, existence of constant challenges between suppliers and demanders, the beginning of descending trend of production and promoting the energy security in its consuming countries have caused besides oil, its substitutes find specific importance. Development and extraction of unconventional resources on one hand have made changes in reservoirs ranking in different areas of the world and has weakened the dependency of consuming countries and on the other hand, it has affected the changing trend of oil price. In this respect, the present study investigates the causal relationship between oil price and supplying unconventional oil and gas during time period of 2000-2015. Two techniques named Granger technique and Toda and Yamamoto technique have been used to investigate the causal relationship. The results of the research show that in all studying period (2000-2015) the unconventional supply is the strong and direct cause for oil price and the indirect and weak price are introduced as the causes of unconventional supply. Also, based on the results, the strong impact of financial markets on the supply of unconventional resources and oil prices has been achieved. On the other hands the results show that unconventional supply will affect the supply of OPEC in the long term (2000-2015). Therefore, this achievement for OPEC countries, as well as Iran, can be used as a result of a strategic change in production policy.