PURPOSE: To provide a polymeric biocidal agent which includes polymerizable compounds having asymmetrical biguanide groups as a constitutional component, and by which the growth of a microorganism can be prevented for a long period and the surface substantially free from the microorganism can be provided.

CONSTITUTION: A polymer including an antimicrobial polymerizable compounds of formula I [A is a polymerizable group; Q is phenylene; R is (CF2)yCF3 (y is 1-20), (CH2)x-O-CxH2x+1 (x is 1-25), formula II (T is H, C1-20 alkyl; n, m and p are 0-99, and the sum thereof is not less than 1), CHR'COOH (R' is H or naturally-existing amino acid side chain), (CH2)xCOOH, formula III or the like], as constitutional components. The polymer is used as the components of a sealant, an antimicrobial surface cleaner, antimicrobial scrub for local use, a coating composition, an adhesive agent, a personal care product, a medical product or the like.