SUMMARY
Possible contributions to neutrinoless double beta (ßß)0? decay in the economical 3-3-1 modelare discussed. We show that the (ßß)0? decay in this model is due to both sources—MajoranaL and Dirac D neutrino masses. If the mixing angle between charged gauge bosons, thestandard model W and bilepton Y , is in range of the ratio of neutrino masses L/D, boththe Majorana and Dirac masses simultaneously give contributions dominant to the decay. As results,constraints on the bilepton mass are also given.