Abstarct: In Oil Industry, from past until today engineers always tried to find a way to produce more oil from reservoirs. In order to do that many methods have been introduced in which the Enhanced Oil Recovery (EOR) was the most important one. In these methods, reservoir engineers recover the remained oil in the reservoir, which is not producible with conventional methods, by todays’ advanced technologies. One of most common methods of EOR is brine injection method into the reservoir by one or more injection wells. This non-producible oil will be swept by the injected brine into reservoir formation and will reach the producing well and will be recovered. This method is commonly used in Iran like other places and since most of Iranian formations are fractured carbonates, in this thesis we tried to investigate the role of fracture inclination on EOR processing in brine injection. Therefore, with laboratory core samples and Coreflood apparatus, we designed some tests to understand the foremost unknown factor. During these tests, firstly we calculated the pre-needed information for the main examination situation then injected brine into the cores. There are five different core samples in this thesis which are unfractured core, single fractured parallel to injection direction, core samples with fractures in 30 degree, 60 degree and 90 degree (perpendicular) to brine injection direction. Finally, it has been observed that the unfractured core have the highest recovery value and after that sequentially fractured cores with zero, 30, 60 and 90 degree have highest recovery values. In conclusion, unfractured reservoirs are the best places for brine injection and after that formations with parallel fractures to injection brine direction are best for producing more oil