  Based on a data sample of an integrated luminosity of 57.4 fb-1 at the
Upsilon(4S) resonance taken with the BaBar detector using the SLAC PEP-II
asymmetric-energy $B$-Factory, hadronic decays of B meson with the final states
D(*) and three pions are studied. The study is performed by fully
reconstructing the exclusive decays of B->D(*)a_{1}(1260) and the non-resonant
modes B->D(*)rho^{0} pi and B->D(*)pipipi. The current status of the study is
presented and a dominant B->D(*)a_{1}(1260) decay is shown.
