Poly(aryl ether ketone) (1) containing alkyl groups was prepared by nucleophilic substitution of 4,4'-difluorobenzophenone (DFBP) with 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane (TMBPA). And co-poly(aryl ether ketone) (2) containing heterocyclic moiety was prepared from DFBP, TMBPA, and 2,6-dichrolopyridine (DCP). The polymers were soluble in common organic solvents, such as N-methyl-2-pyrroridone, tetrahydrofurane, chloroform, and cyclopentanone at room temperature. Thermogravimetry of the polymers showed good thermal stability, indicating that a 5% weight loss of the polymer (1) and (2) were observed at 421°C and 395°C in air respectively. Glass transition temperature of the polymers ranged from 206 to 212°C. Transparency of the polymers at 365nm was almost 40-50% . The polymers showed low water absorption of 0.1-0.2%. The polymers acted as a negative-working photoreactive polymer by UV radiation. Adhesion to copper substrate of the polymer (2) was improved compared with the polymer (1). Then the polymer (2) was capable to resolve a 20μmφ hole pattern on copper plating surface when a 10μm-thick film was used. The dielectric constant and dissipation factor of the polymer (2) were 2.71 and 0.0043 at 12GHz respectively.