An air drying high solid coating composition containing 90% or more of solid components and consisting of (1) 95 - 50 parts by weight of low viscosity alkyd resin having an oil length of 60 or higher and a viscosity of Z.sub.4 or lower, (II) 5 - 50 parts by weight of 1,1-bis-(1'-methyl-2'-vinyl-4',6'-heptadienoxy)-alkane, and if necessary, (III) other components such as pigments, organic solvents and additives. The coating composition is quite effective in the prevention of air pollution and the saving of resources.