Pipe flows of dilute aqueous polymer solution are studied experimentally. Measurement is made for two different pipe-sizes using 0.5 to 70 wppm solutions of polyethylene oxide of approximate molecular weight of 6×10⁶. The results show : 1) the friction coefficient is dependent, under a certain condition, on a heading tank water level and this phenomenon is not due to pressure : 2) the Toms effect is promoted at relatively small Reynolds number by decreasing the pipe diameter, increasing the concentration and /or the heading tank level : 3) an unusual pressure drop occurs upstream immediately before the orifice plate : and 4) interesting behavior of dye filaments in pipe flow is observed in the transition and turbulent flow regions.