Debris flow rheology is always a debatable topic due to wide range of particle size and concentration present in suspension. Prediction of debris flow characteristics with varying densities and viscosities becomes the key step in debris flow modelling and mitigation strategies. Hence, in this study influence of solid volume fraction (0.20 to 0.75) and percentage of coarser material have been investigated on rheology of debris flow at shear rate from 0.01 to 1400/s experimentally. Digital hybrid rotational rheometer with vane rotor, and parallel plate geometry systems have been employed to investigate the rheology of reconstituted debris flows. Material have been collected from the bank of Simpanng Pulai on the way of Cameron highland. Sample were prepared with restructured dry, and sieved sediment which was mixed with water at different solid volume fraction. The Aggregation of data collected from optimized tested sediment-water mixture concludes that, increase in solid volume fraction (Cv) increases the yield stresses and viscosity of debris flows. The debris flow tested samples behaved like non-Newtonian fluid and followed the Hershel Bulkley model. Ranges of consistency coefficient (k) and pseudoplastic index (n) observed from 0.00035 to 10.43Pa-sn and 0.16 to 1.91 at different solid volume fraction. Further, yield strength was markedly influenced by replacing of 6 coarser particles (sand) with finer material in the sample (S3 and S4). Result suggest that determination of yield stress is key parameter in describing the initiation and mobilization of debris flows, which is significantly affected by solid volume fraction, and particle size present in suspension. © School of Engineering, Taylor�s University.