An experiment of upward air-glycerol aqueous solution two-phase annular flow is made to collect the information on the effect of liquid viscosity on interfacial friction and the main parameters which characterize gas-liquid interface : radial distribution of liquid-phase, wave height and wave frequency. The experimental results show that both the wave height and interfacial friction factor are larger than those in more viscid liquid system. Further, it is confirmed that the mathematical model proposed in the previous report to express the characteristics of gas-liquid interface can also be applied to air-glycerol aqueous solution annular flow. And, a new relationship is introduce between the interfacial friction factor and the parameters characterizing gas-liquid interface with consideration for the effect of wave shape.