Increase in traffic load in terms of numbers of axles and high pressure from heavy vehicles resulted into traffic related pavement distresses. Modified asphalt binder is one of the approaches to improve pavement performance. Natural fibers have become a research focus for scientist & engineering. Type of natural fibers, their surface treatment & reinforcement of asphalt concrete with natural fibers are presented. Generally the review demonstrated an improvement in the fatigue life & structural resistance to distress occurring in pavement when modified. Generally a bituminous mixture is a mixture of course aggregate, fine aggregate, filler & binder. A hot Mix Asphalt is a bituminous mixture where all constituents are mixed, placed & compacted at high temperature. HMA can be Dense Grade Bitumen (DGM) known as Bituminous Concrete (BC) or gap graded known as Stone Matrix Asphalt (SMA). SMA requires stabilizing additives composed of cellulose fiber to prevent drain down of the mix. In the present study an attempt has been made to study the effects of use of a natural fiber (SISAL FIBRE as stabilizer in SMA) & as an additive in BC.For preparation of the mixes aggregate gradation has been taken as per Morth Specification, binder content, has been varied regularly from 4% to 7% & fire content varied from 0% to maximum 0.5% of total mix. Then the BC [&SMA] mixes prepared are subjected different performance test like Drain down Test, Static Indirect Tensile strength & Static creep test to evaluate the effects of fiber additions on mix performance.