Microbial synthesis of functional polymers has become increasingly important for industrial biotechnology. For the first time, it became possible to synthesize controllable composition of poly(3-hydroxyalkanoate) (P3HA) consisting of 3-hydroxydodecanoate (3HDD) and phenyl group on the side-chain when chromosome of Pseudomonas entomophila was edited to weaken its β-oxidation. Cultured in the presence of 5-phenylvaleric acid (PVA), the edited P. entomophila produced only homopolymer poly(3-hydroxy-5-phenylvalerate) or P(3HPhV). While copolyesters P(3HPhV-co-3HDD) of 3-hydroxy-5-phenylvalerate (3HPhV) and 3-hydroxydodecanoate (3HDD) were synthesized when the strain was grown on mixtures of PVA and dodecanoic acid (DDA). Compositions of 3HPhV in P(3HPhV-co-3HDD) were controllable ranging from 3% to 32% depending on DDDA/PVA ratios. Nuclear magnetic resonance (NMR) spectra clearly indicated that the polymers were homopolymer of P(3HPhV) and random copolymers of 3HPhV and 3HDD. Their mechanical and thermal properties varied dramatically depending on the monomer ratios. Our results demonstrated the possibility to produce tailor-made, novel functional PHA using the chromosome edited P. entomophila.