  We analyze the $\gamma N\to\pi N$ process in the negative parity channel with
Hamiltonian effective filed theory which is successful in studying the nucleon
resonances associated with the meson-nucleon scattering and lattice QCD
simulations. We provide the scattering amplitude of pion photoproduction and
extract the electric dipole amplitudes $E_{0+}$. The triquark component in
$N^*(1535)$ is important for improving the consistence between our results and
the experimental data.
