In this research work, Corn Cob Ash is partially utilized as supplementary cementitious material (SCM) for cement and addition of different percentage of artificial fibers as micro reinforcement has been used to find the effect on fresh, mechanical and microstructural properties of HPC through testing. Firstly, the mechanical properties of HPC with different Corn Cob Ash (CCA) contents of 5, 10, 15, 20 and 25% by weight of cement were tested and the results showed that HPC with 15% CCA is the most economical replacement and it exhibits the better mechanical properties close to the reference concrete. Subsequently, 15% CCA was taken constant for PP and PS series mixes with 0.1, 0.2, 0.3 and 0.4 % addition of artificial fibers (polypropylene and polystyrene fiber by weight of binders) into HPC to evaluate its effects on slump, compressive strength, split tensile strength, flexural strength, modulus of elasticity, ultrasonic pulse velocity and microstructure. The results revealed that 15% of CCA replaced mixes along with 0.4% of artificial fibers showed better in mechanical properties and microstructure. However, above 15% of Corn Cob Ash replacement was showed poor on mechanical properties of HPC, compared to the control mix (C0) without CCA and fibers.