Abstract: Polymers have been used in oil well cementing for improving the properties of cement slurry. Polysaccharides and their derivatives are mostly used as multifunctional additive in cement slurry. But these polymers present number of limitations at high temperature. Polysaccharides do not reveal an appropriate thickening of viscosity in cement slurry at high temperature which turn gives the fluid loss, gas migration and loss of economics. It is necessary to use such type of polymer in cement slurry that increases viscosity at high temperature. Therefore, this study present Hydroxypropylmethylcellulose (HPMC) polymer that is able to increase viscosity at high temperature and improve the properties of cement slurry. Laboratory experiments were performed to determine the characteristics of HPMC based cement slurry. The viscosity of 2 wt.% solution of HPMC polymer was determined at various temperatures. Further 0.20-0.50 gallon sack-1 concentration of HPMC polymer was used in cement slurry to evaluate the API properties of HPMC based cement slurry in term of rheology, free water, fluid loss, thickening time and compressive strength. It was observed that HPMC polymer was stable at high temperature and increases viscosity at elevated temperature. In cement slurries HPMC polymer resulted less than 50 mL of fluid loss; zero free water and predictable thickening time as well as enhanced final compressive strength with some other additives. The experimental result showed that HPMC has significantly improved the properties of cement slurry at high temperature.