A vehicle window glass assembly comprises a window glass and a plurality of parallel, electric heating strips disposed on the window glass. The distance between adjacent two of the heating strips at least at portions thereof disposed in a central region of the window glass being in the range of 20 to 28 mm so that a quantity of heat generated by the heating strips per unit area can be smaller, i.e., 0.80 to 0.95 times of a reference electric power or a supply power for the heating strips can be 0.80 to 0.95 times of a reference electric power. The reference electric power is a power necessary for causing a surface temperature of a comparable window glass with comparable heating s trips to rise up to 90% of an equilibrium temperature in the range of 35 to 45.degree. C., in 5 to 10 minute's time after energizing of the comparable heating strips starts, under the condition where the distance between adjacent two of the comparable heating strips at portions thereof disposed in a central region of the comparable window glass is in the range of 29 to 33 mm, a room temperature is 20.degree. C., and windless.