PURPOSE: To obtain an alkoxysilylated acryl emulsion which has excellent storage stability and can give a coating film excellent in durability and weather resistance by forming the core and the shell with specified monomer component under specified conditions.

CONSTITUTION: This emulsion is a core/shell type emulsion in which the sore of an emulsified particle and its shell are different in composition and prepared by emulsion-polymerizing a mixture of a monomer component I for forming the core comprising 50-99wt.% 1-18 C alkyl (meth)acrylate (A), 1-20wt.% organosilicon compound represented by the formula: R1SiX3 (wherein R1 is a monovalent organic group having a polymerizable double bond; and X is 1-4C alkoxyl) and 0-30wt.% comonomer with a monomer component II for forming the shell comprising 50-99wt.% component A; 1-20wt.% organosilicon compound represented by the formula: R2R3(3-n)SiYn (wherein R2 is R1; R3 is 1-4 C alkyl; Y is X; and n is 1 or 2) and 0-30wt.% comonomer in an I/II weight ratio of 50/50 to 90/10 in the presence of a reactive surfactant.