A new method to measure viscoelasticity of liquids through the surface loading analysis was proposed, and performance of a rheometer based on the method was shown. An impedance head which could detect force applied on itself and its acceleration was employed, so that apparent mass could be estimated as transfer function. A small slide glass plate was suspended from a tip of the impedance head as a measuring part, and the other tip of the device was attached to a vibrator. The mechanical impedance of liquids was estimated from difference between the transfer functions when the plate immersed in the liquids and those in the air. Then, the storage and loss moduli were converted from the mechanical impedance as functions of frequency, ω, in the range of 10² to 10⁴ rads^-1. Viscosities of pure viscous liquids from 0.1 to 20 poise and also a unique viscoelasticity of an aqueous detergent system were measured rather correctly in the frequency range.