The flow of polymer solutions form a reservoir through a capillary to air is experimentally investigated. The flow patterns in a reservoir, the axial pressure distributions in a capillary, and pressure fluctuations in both the capillary and the reservoir are measured. Then, the influence of the flow pattern in the reservoir on the pressure loss in a capillary and on the instability of the extruded jet are discussed. It was found that the pressure loss in the case of an unstable flow was larger than that in the case of an stable flow. And the onset of the unstable flow is discussed.