As a promising structural material for complex shape parts in medical and aerospace engineering, selective laser melted (SLM) Ti-6Al-4V has been studied widely. Furthermore, microstructures, which can be tailored by altering processing parameters, dominates material properties. Hence, to improve the material properties to meet requirements of applications, the relationship of microstructures and properties is worth studying. This thesis examines the influence of microstructures in SLMed Ti64 alloys on mechanical properties, simulation of various microstructures by finite element analysis (FEA) was carried out to predict the behavior of SLMed Ti64, and experimental tests was carried out to validate the predictions.