Zeeman coherences with Am = 1 and Am=2 are observed in the ground state of natural rubidum vapor optically pumped with a laser diode pulse train. The laser pulse of approximately 200ps at 780 nm are produced by gain-switching through direct modulation of the inject current of the laser. Δm=1 coherences are detected by a probe beam using the polarization speotrosoopy technique, while the forward scattering spectroscopy technique is used to detect the Δm=2 coherences.