Abstract: Current source grid-connected inverter（CSGCI） is well known as its no shoot-through problem and superior boost characteristics. However, existing CSGCI not only needs to set the overlap time, but also has the problem of high frequency common mode leakage current. To overcome these imperfections,a new transformerless CSGCI with non-overlapping time（TCSGCI-NT）topology and its unipolar SPWM strategy are proposed. Then,the operating modes and common-mode leakage current of the TCSGCI-NT are analyzed. The commutating current during mode conversion is explored in detail. The analysis result shows that the TCSGCI-NT has the advantages of the non-overlapping time and can completely meet the condition of eliminating common-mode leakage current. Finally,the experimental results verify the correctness of the TCSGCI-NT circuit design and theoretical analysis.