The XENON experiment, in operation at the deep underground laboratory at Gran Sasso (LNGS) in Italy, is designed to search for Dark Matter. It can detect weakly interacting massive particles (WIMPs) scattering off a liquid xenon nucleus. The energy, position and type of the interaction can be identified by observing the small charge and light signals after a particle interacts with a xenon nucleus.

The current detector - XENON100 - has been operating in dark matter detection mode at LNGS since the beginning of 2010. We will show the current upper limits for the WIMP-nucleon elastic cross-sections and will describe the statistical model that has been used to analyze XENON100 data. In order to increase the experiment sensitivity, a 1 ton scale detector -XENON1T - is currently developed. Preliminary results from MC simulations of the nuclear recoil (NR) and the electromagnetic recoil (ER) bands calibration for XENON1T will be presented.