Abstarct: Concrete structures may experience different temperature conditions during their lifetime. However, it is very important to evaluate the behavior of these structures when exposed to high temperatures. Crushing concrete at high temperatures is the most important factor in reducing its fire resistance. Crushing is usually caused by high pressure in the pores and heat stress. Therefore, it is very important to study the effects of temperature on concrete, especially fiber-reinforced concrete, which is expected to have high strength. Exposure of concrete to high temperatures is one of the most severe conditions to which concrete may be exposed. In this research, ABAQUS finite element software was used to model three concrete beams made of high strength concrete containing 100, 150 and 200 MPa compressive strengths. Then the effect of temperature on bending strength as well as fracture energy of concrete with 2% fibers at room temperature and temperatures of 200, 500 and 700°C was investigated. using three-point flexural loading on prism specimens of 40×40×160mm dimensions. The results showed that the flexural strength of the specimens had the highest value at 200°C and the lowest value at 700°C. On average, for all three specimens, the diagram showed an increase of bending strength by 15% at 200°C, but after time reached a temperature of 700°C, the diagram continued its downward trend, reaching 34% below the room temperature. This is due to the gradual progression of hydration and the pozzolanic reaction over longer periods at high temperatures. Increasing The concrete compressive strength led to higher resistance under higher temperatures and higher fracture energy.