Recently, a new class of topological insulators with antiperovskite structure have been theoretically proposed. A few of the proposed structures have been realized experimentally and their topological character have been confirmed. In this project we will search for new topological insulators in this class by focusing on materials whose properties have not yet been confirmed. In particular, we will focus on structures with chemical composition A3BO, where A=Ca,Sr,Ba,Eu,Yb and B=Sn,Pb, as well as A=La,Pr and B=In. Many of the structures that we will study have not yet been synthesized experimentally. We will use density functional theory calculations to investigate the properties of these compounds. Our aim is to make theoretical predictions and suggestions for experiment that could potentially lead to discovery of new topological insulator materials.