Abstract: The Large High Altitude Air Shower Observatory (LHAASO), the largest ground based Gamma Ray detector array, is built up and has been operated for months. Many VHE gamma ray sources have been observed including well known sources such as the Crab and the blazar Mkr421. With many sources found having strong emission of gamma rays in the UHE (> 0.1 PeV) band, LHAASO starts the era of the UHE gamma ray astronomy. With its unprecedented sensitivity at energies above 10 TeV and extremely high background rejection capability, super-PeV gamma-like events, including the record high energy of 1.4 PeV, are detected for the first time in history. In addition, with the measurement of the SEDs of several galactic gamma sources above 0.1 PeV, LHAASO reveals that our galaxy is full of PeVatrons, very powerful accelerators which as in the case of Crab pose strong challenges to models and fundamental theories. Those exciting discoveries enable us exploring for hadronic PeVatron sources which are the origin of cosmic rays. LHAASO could separate individual species of charged cosmic rays, such as protons or iron nuclei, at energies around the “knee”. The knees of the spectra of cosmic rays are expected to be clearly identified with sufficient statistics. The study of the highest energy photons with LHAASO provides the opportunity to check the validity of fundamental laws, such as Lorentz Invariance.