The invention relates to a pharmaceutical composition of solid dosage form containing a pazopanib, which is used in pharmacy and medicine, in particular for the treatment of advanced renal cell carcinoma and sarcoma of soft tissue, and to a process for its preparation. The pharmaceutical composition comprise pazopanib in an amount of 50 to 80 w/w % with a specific particle surface area of 1000 -2000 m2/kg, distributed by size D90 35-45 μιτι, D 50 5-12 and D10 NMT 1-3 μιη and as excipients microcrystalline cellulose, povidone, sodium starch glycolate and magnesium stearate. An advantage of a pharmaceutical composition according to the invention is its good pharmaceutical and biological availability and the process for its preparation is easily manageable and controllable and ensures the preparation of a stable dosage form with a good rate and degree of release of the active substance.