In the past decades, huge efforts have been put into unraveling the mysteries of neutrino mass generation (Majorana or Dirac). Neutrinoless double beta decay is one of the golden channels to detect Majorana neutrinos. We develop Time Projection Chambers (TPC) with high pressure gaseous 136Xe to search for Neutrinoless double beta decay. The TPCs use Micro-pattern gas detectors (Micromegas) as the charge readout, utilizing their tracking capability for event identification. A prototype detector holding 20 kg of gaseous xenon was successfully built and commissioned. The design and construction progress of a full-size detector containing 140 kg of xenon will be introduced. Track reconstruction and signal identification algorithms were also studied and developed, demonstrating significant signal-background discrimination power.