M31 proposes the competitive 6.5 track high density and low power standard cells (HDSC) for 22nm/28nm technology nodes. To get the smallest cell area, M31 chooses the proper high density cell layout for different driving strength, also makes rich sets of combo cells. The total low power solution is also provided with Low Power Optimization Kit (LPKT) and Power Management Kit (PMK) to reduce dynamic and static power. Compared with other conventional 7 track in industry, M31’s 6.5 track cell library could save 8% area and 13.37% total power in the same operation frequency and operation voltage (benchmarked by CPU case) which means M31 could provide the smallest areas of cell library in the 22nm/28nm technology nodes to obtain best cost efficiency.