The object of the present invention is to develop a novel vector. Preferably, the object is to develop a novel vector which can be stably retained in bacteria of the genus Ralstonia, Cupriavidus or Wautersia without any antibiotic-due selective pressure and has no transferability by conjugation. Another object is to provide a strain which can stably produce polyhydroxyalkanoate using the vector, and a method for producing a polyhydroxyalkanoate using the strain. The present invention provides a novel recombinant vector which contains an origin of DNA replication functioning in bacteria of the genus Ralstonia, Cupriavidus or Wautersia. Particularly, the transformant, which is obtained by using a recombinant vector which contains the origin of DNA replication functioning in bacteria of the genus Ralstonia, Cupriavidus or Wautersia and contains a region for a recombinant vector stabilization (par region) can make the vector to be stably retained in bacteria, and can efficiently produce a polyhydroxyalkanoate.