  The structure of the Roper resonance as a hybrid baryon is investigated
through studying the transitional amplitudes in J/psi-> p\barN*, N*\barN*
decays. We begin with perturbative QCD to describe the dynamical process for
the J/psi-> 3\bar q+3q decay to the lowest order of \alpha_s, and by extending
the modified quark creation model to the J/psi energy region to describe the
J/psi-> 3\bar q+3q +g process. The non-perturbative effects are incorporated by
a simple quark model of baryons to evaluate the angular distribution parameters
and decay widths for the processes J/psi-> pbar N*,N*bar N*. From fitting the
decay width of J/psi->gamma p pbar to the experimental data, we extract the
quark-pair creation strength g_I=15.40 GeV. Our numerical results for
J/psi->pbar N*,N* bar N* decays show that the branching ratios for these decays
are quite different if the Roper resonance is assumed to be a common $3q$ state
or a pure hybrid state. For testing its mixing properties, we present a scheme
to construct the Roper wave function by mixing |qqqg> state with a normal
|qqq,2s> state. Under this picture, the ratios of the decay widths to that of
the J/psi->p pbar decay are re-evaluated versus the mixing parameter. A test of
the hybrid nature of the Roper resonance in J/psi decays is discussed.
