Novel poly(phthalazinone ether sulfone ketone) (PPESK) synthesized in our laboratory, has shown good solubility and very high glass transition temperature (Tg), in the range of 263±305?,by the virtue of the introduction of twist non-coplanar phthalazinone moieties into the polymer’s backbone. The resin was dissolved in organic solvent, and baked to form varnish. The effects of polymers’ sulfone/ketone molar ratios (S/K) and intrinsic viscosity on the coating’s properties were studied, either. The result showed that the varnish has excellent adhesion to metal,impact resistance and flexibility properties when S/K is 8/2 and polymer’s intrinsic viscosity is about 0.50~0.60dL/g. The pigments were ulteriorly mixed into varnish to form color coating.The coating has excellent heat resistant and anti-corrosion properties, and can be used in the high temperature system..