The role of the synthetic route in Fischer-Tropsch synthesis (FTS) over the BaÀ Co-Mn catalysts was investigated in the fixed bed micro reactor. Synthesis of catalysts through inorganic complex [Ba 0.5 Co 0.34 Mn 0.66 (btc) 2 (H 2 O) 5 ] (1) led to enhancement of the surface area and decreased particle sizes. Therefore, the catalytic activity of catalysts prepared this way was improved as well as their olefins and C 5 + selectivity. The synthesised catalysts prepared by inorganic precursor had higher selectivity to heavier hydrocarbons at high pressure in comparison to lower pressure.