Development of low-cost nontraditional intrinsic luminescence (NTIL) polymers containing auxochromophores and understanding their luminescence characteristics are highly desirable. In this paper, alternating vinylarene-carbon monoxide copolymers (PK-X, X = H, Ph, Bu-t, (OBu)-Bu-t, F, and Cl) were, for the first time, reported as simple and efficient NTIL polymers, which were facilely and precisely prepared by palladium-catalyzed coordination copolymerization of vinylarene and CO. These nonconjugated polymers emitted intrinsic blue light in both concentrated solutions and solid powders by the clusterizationtriggered emission mechanism. Theoretical calculations and singlecrystal analysis of the small molecular model clearly confirmed that through-space intra- and interchain interactions by n-pi and pi-pi modes between the carbonyl and the phenyl groups collectively formed clusteroluminogens. The copolymer quantum yields greatly improved regardless of the introduction of an electron acceptor or donor. The chloride-substituted copolymer had a high quantum yield of up to 44.8% and showed great potential as a photoluminescent material for improving the utilization of sunlight.