There is provided a low-staining agent which can outstandingly improve an anti-staining property and a property of preventing penetration of a staining substance when it is added to an aqueous paint, which does not affect a weather resistance and a water resistance of the paint, and which has an excellent compatibility with the aqueous paint. The present invention also relates to a low-staining aqueous paint composition to which said low-staining agent is added. The present invention relates to an aqueous paint low-staining agent which is a modified condensation product of alkoxysilane having at least one polyoxyalkylene group and an alkoxyl group, wherein a repetition unit of said polyoxyalkylene group has 1 to 4 carbon atoms, and said alkoxyl group has 1 to 4 carbon atoms. In particular, it is preferable that the polyoxyalkylene group is a polyoxyethylene group and the alkoxyl group is an ethoxy group.