To better understand traumatic brain injury (TBI), various laboratory animal experiments have been developed. However, there lacks an effective scaling to connect animal TBI models with human brain injuries. With the help of the finite element (FE) model, brain mechanical responses such as strains can be predicted, and hence can serve as a parameter to facilitate animal to human scaling, as these tissue-level strains directly link to neuronal damage. In this thesis, first, a comprehensive comparison of brain strains between animal TBI models and human TBI cases was conducted. Then, a brainstrain-based scaling law between mouse and human was developed, which could serve as a guideline for closed head neurotrauma model design. Lastly, a novel and high mesh quality marmoset brain FE model was developed, which was used to enrich scaling law to non-human primates. In summary, the comparison method, scaling law, and new marmoset FE model, all together could help better represent human real-world TBI using laboratory mouse and marmoset TBI models, hence improving prevention, diagnostics, and therapeutics.