Pressurized circulating fluidized bed technology is promising in coal & biomass combustion and gasification. To get more detail information of pressure effects on gas-solids flow behaviors in a circulating fluidized bed reactor, we built a novel pressurized multi-stage circulating fluidized bed (MCFB) reactor a cold pilot setup with 14.5 m height. The experiment was carried out at the elevated pressure up to 0.9 MPa with the use of polystyrene particles (rho(s) = 1020 kg/m(3), d(p) = 400 mu m). We used differential pressure transducers to collect the pressure data and monitor the operating condition. Local solids holdup was measured by the optical fiber probes. Our results showed that the apparent solids holdup presented multi-flow regimes in the axial direction of MCFB. Under the same solids circulation rate and superficial gas velocity, the apparent solids holdup and local solids holdup decreased, and the axial flow structure and radial profiles of solids holdup became more uniform with increasing the pressure. When the fluidized gas mass flow rate and the solids circulation rate were kept the same, the solids holdup at axial and radial directions increased with the pressure. The speed of gas-solids flow development was different at various pressures with a slower speed at high pressure under the same solids circulation rate and superficial gas velocity. As a result, the elevated pressure significantly influences the gas-solids flow behaviors and provides better riser performance with good gas-solids contacting and mixing by the uniform radial and axial distributions than the atmospheric pressure at the same superficial gas velocity. (C) 2018 Elsevier Ltd. All rights reserved.