We present a theoretical model for Type Ib supernova ( SN ) 2006jc . We calculate the evolution of the progenitor star , hydrodynamics and nucleosynthesis of the SN explosion , and the SN bolometric light curve ( LC ) . The synthetic bolometric LC is compared with the observed bolometric LC constructed by integrating the UV , optical , near-infrared ( NIR ) , and mid-infrared ( MIR ) fluxes . The progenitor is assumed to be as massive as 40 M _ { \odot } on the zero-age main-sequence . The star undergoes extensive mass loss to reduce its mass down to as small as 6.9 M _ { \odot } , thus becoming a WCO Wolf-Rayet star . The WCO star model has a thick carbon-rich layer , in which amorphous carbon grains can be formed . This could explain the NIR brightening and the dust feature seen in the MIR spectrum . We suggest that the progenitor of SN 2006jc is a WCO Wolf-Rayet star having undergone strong mass loss and such massive stars are the important sites of dust formation . We derive the parameters of the explosion model in order to reproduce the bolometric LC of SN 2006jc by the radioactive decays : the ejecta mass 4.9 M _ { \odot } , hypernova-like explosion energy 10 ^ { 52 } ergs , and ejected ^ { 56 } Ni mass 0.22 M _ { \odot } . We also calculate the circumstellar interaction and find that a CSM with a flat density structure is required to reproduce the X-ray LC of SN 2006jc . This suggests a drastic change of the mass-loss rate and/or the wind velocity that is consistent with the past luminous blue variable ( LBV ) -like event .