Grid-connected inverters are the critical components of distributed generation system because of their function as an efficient interface between renewable energy sources and utility. Recently, there has been an increasing interest in the use of Transformerless Inverter (TI) for low voltage single phase grid-connected Photovoltaic (PV) system due to high efficiency, low cost, small size, and weight compared to those with a transformer. This research review emphases on the TI topologies, which are categorized into four primary groups based on the structure, leakage current, and device characteristics. Various configurations like H5, H6, Highly Efficient and Reliable Inverter Concept (HERIC) and Neutral-Point Clamped (NPC) are offered, associated and analyzed based on leakage current in the topology, component count and ratings, benefits and difficulties. © 2020, Research Trend. All rights reserved.