Majorana particles have the special property that they are their own antiparticles. Neutrinos, as the only neutral elemental fermions, can be such particles. Their Majorana nature, if confirmed, may help explain the tiny neutrino masses we observe today. Neutrinoless double beta decay search is the most sensitive experimental probe for the Majorana nature of neutrinos. It can also shed light on the absolute mass scale of neutrinos, and lepton number violating processes.
EXO-200 is one of the largest operating double beta decay experiments in the world. This 200 kg enriched liquid xenon detector has been taking low background physics data at the Waste Isolation Pilot Plant (WIPP) in New Mexico since early May 2011. The collaboration has recently finished analyzing the first two-year of data with an exposure of 99.8 kgyr of Xe-136, producing one of the most sensitive search results for neutrinoless double beta decay. During the talk, I will discuss the latest result from EXO-200 and the prospects of neutrinoless double beta decay search with EXO-200 as well as the next generation experiment nEXO.