We have performed detailed temporal and time-integrated spectral analysis of 286 bursts from SGR J 1550 - 5418 detected with the Fermi Gamma-ray Burst Monitor ( GBM ) in January 2009 , resulting in the largest uniform sample of temporal and spectral properties of SGR J 1550 - 5418 bursts . We have used the combination of broadband and high time-resolution data provided with GBM to perform statistical studies for the source properties . We determine the durations , emission times , duty cycles and rise times for all bursts , and find that they are typical of SGR bursts . We explore various models in our spectral analysis , and conclude that the spectra of SGR J 1550 - 5418 bursts in the 8 - 200 keV band are equally well described by optically thin thermal bremsstrahlung ( OTTB ) , a power law with an exponential cutoff ( Comptonized model ) , and two black-body functions ( BB+BB ) . In the spectral fits with the Comptonized model we find a mean power-law index of -0.92 , close to the OTTB index of -1 . We show that there is an anti-correlation between the Comptonized E _ { peak } and the burst fluence and average flux . For the BB+BB fits we find that the fluences and emission areas of the two blackbody functions are correlated . The low-temperature BB has an emission area comparable to the neutron star surface area , independent of the temperature , while the high-temperature blackbody has a much smaller area and shows an anti-correlation between emission area and temperature . We compare the properties of these bursts with bursts observed from other SGR sources during extreme activations , and discuss the implications of our results in the context of magnetar burst models .