Silica slurry flow is multiphase flow consist of liquid and solid particles. Some parameters such as pipe geometry, particle solid size, percentage and density of solid concentration effect flow performance. Drag Reducing Agents (DRA) is one of the method to improve flow efficiency that used as agents to reduce power losses in pipeline. Biopolymer is one of the popular DRA due to environmental friendly and abundant resources. Spiral pipe is one of the method to increase drag reduction in certain flow rate, moreover can prevent sedimentation in pipe bottom and generate homogeneity particles distribution. Silica sand with density 2300 kg/m3, and particle diameter 1 mm. Particle weight concentration is 50%. Experimental conducted by circulating silica slurry and CMC in test pipes. Pressure transducer used to obtain pressure drop data between two point measurements. Objective of this research is to investigate pressure drop reduction using CMC additive 300 ppm, 600 ppm, and 900 ppm mixed with silica slurry in spiral pipe with ratio P/Do 3.4; 7.0; and 11.6. Maximum drag reduction is 900 ppm in spiral pipe ratio P/Do 7,0 = 25%, and P/Do 11,6 = 29%. Silica slurry homogeneity reached about 95% in spiral pipe ratio P/Do 7.0 with flow velocity 1,5 m/s.