PURPOSE: To obtain a low-toxicity primer compsn. excellent in storage stability by compounding an alkoxylated organosilicon compd., a volatile low-molecular organosiloxane, and an org. titanic ester.

CONSTITUTION: A primer compsn. comprises 100 pts.wt. alkoxylated organosilicon compd. represented by the mean unit formula, 10-100,000 pts.wt. volatile low-molecular organosiloxane having a b.p. at 760mmHg of 250°C or lower, and 0.1-100 pts.wt. org. titanic ester. In the formula, R1 is an optionally substd. monovalent hydrocarbon group; R2 is a monovalent hydrocarbon group capable of reacting by addition reaction or condensation; R3 is alkyl; and 0≤a≤3, 0≤b≤3, and 2≤c≤4 provided 2≤(a+b+c)≤4. The organosiloxane is a diluent and dispersant of the organosilicon compd. and the titanic ester, and is used to adjust the compsn. to a viscosity suitable for its application.