The electrical resistivity, microhardness, tensile strength and elongation of rapidly solidified Cu-xwt.%Sn (x=7, 13.5, 20) hypoperitectic alloys are investigated, and the relationships between cooling rate and properties of the alloys are further analyzed theoretically. It is found that, under rapid solidification, the microstructure is refined and the amount of grain boundary increases, and the scattering of free electrons is thus intensified, resulting in the rise of alloy resistivity. Provided that the value of grain boundary reflection coefficient r is about 0.992, the electrical resistivity of the alloys can be theoretically analyzed by the M-S model. With the increase of cooling rate, the microhardness and tensile strength of alloy foils increase linearly, but the elongation decreases within the range of 1.0%—4.6%.