Concrete nowadays plays a very important role in the construction of various structures. The high compressive strength of concrete is an indicator that makes it reliable for structural applications in the construction industry and infrastructure. On the other hand, numerous concrete weaknesses such as brittle behavior, low tensile strength and rapid expansion of cracks have led to the use of fibers in concrete matrix and construction of fiber reinforced concrete (FRC) to remove defects. One of the fibrous concrete substrates is an engineered cementitious composite (ECC) that is made up of the concrete matrix with the addition of polyvinyl alcohol (PVA) fibers, and efficiently increases its tensile strain capacity. The purpose of this study was to investigate the effect of polyvinyl alcohol and polypropylene fibers, aggregate type, limestone powder, micro-silica and nano-SiO2 on mechanical properties of engineered cementitious composite. 12 engineered cementitious composites mixtures with various materials were designed and tested for compressive strength, flexural strength, tensile strength, and durability against freeze-thaw cycling. From each mixture, three 50 mm cubic specimens were prepared for the compressive strength test, two 30 x 100 x 350 mm prism specimens were prepared for the four-point bending test and they were tested at the age of 14, 28 and 60 days. Freezethaw cycling test was conducted in two steps: In the first step, 70 mm cubic samples were used to measure mass and lengths loss before and under freeze-thaw action of 100, 200 and 300 cycles and In the second stage, the flexural strength test was performed on 30 x 100 x 350 mm prism specimens, under freeze-thaw action of 300 cycles, and the results were compared with control specimens. The results indicated that the use of polypropylene fibers instead of PVA fibers increased the deformation of the middle of the span and reduced its rupture modulus. Additionally, the use of Nano-SiO2 for mixtures PP-containing fibers increased compressive strength, especially at 60 days, and the addition of micro-silica (15% by weight of cement) to ECC mix, increased compressive strength, tensile strength and formability. Keywords engineered cementitious composite (ECC), Compressive strength test, four-point bending test, freeze-thaw cycling test, Polyvinyl alcohol fibers, polypropylene fibers, slag, limestone powder, micro-silica, nano-SiO2