Status of the large high altitude air shower observatory project

The Large High Altitude Air Shower Observatory (LHAASO) project is a multipurpose project. The main scientific tasks can be summarized as follows: (1) searching for galactic cosmic ray origins through gamma ray source detection above 30 TeV; (2) wide field of view survey for gamma ray sources at energies higher than 100 GeV; (3) energy spectrum measurements for individual cosmic ray species from 30 TeV to 10 PeV. To target above tasks, a complex detector array is designed. This paper describes the progress on the research and development of all kind of detectors. Construction and operation of a prototype detector array at Tibet site with 4300 m a.s.l. are also presented.