This research deals with the earth's inner core. Many properties of the earth's inner core are not well determined, with seismic studies often giving ambiguous or contradictory results. Some of these features include inner core density and Q structure, and the recent suggestions of heterogeneity and/or anisotropy. For all of these properties, there are discrepancies between models obtained from body wave studies and those from normal modes. This research will address these issues by systematically examining a variety of data sets which constrain inner core structure, including ISC travel times, GDSN waveforms, and normal modes. The aim is to find the simplest inner core models consistent with the data, and estimate the resolution associated with these models. This research has direct application to models of the structure and convection of the earth's core and secondary effects such as the variability of the earth's magnetic field.