Experiments of dense-phase pneumatic conveying of pulverized coal with different mean particle sizes were carried out in an experimental test facility by using nitrogen with the conveying pressure up to 4 MPa. The pressure drop across the vertical bend was analyzed with experimentation and analytical calculation. The results showed that the pressure drop due to solids motion played a major role for the total pressure drop. At the same mass flow rate，the pressure drop due to kinetic energy loss increased with the increase in superficial velocity，while the pressure drop due to solids friction decreased. At the same superficial velocity，the pressure drop due to solids friction increased with the increase in solids volume fraction. The solids friction factor slightly decreased with the increase in superficial velocity，and was independent of particle size or mass flow rate.