MTCMOS (Multi Threshold CMOS) technology provides a solution to the high performance and low power design requirements of modern designs. Low Vth and high Vth transistors are used in MTCMOS technology. Low Vth transistors are used to implement the desired functions. High Vth transistors are used to cut off the leakage current. The MTCMOS circuits however suffer from high energy overhead during the transitions between the active and stand by modes. In this paper, the authors propose a new special flip flop which keeps a valid data during the sleep mode, develop a methodology which takes in to account the new design issues related to the MTCMOS technology.