SUSY physics with early data: understanding the ATLAS detector and the backgrounds

We review the strategy for searching for the R-parity conserving SUSY particles at the ATLAS detector at LHC. Results are focused on in the early stage of the collision, and techniques for understanding detector-performance and estimating Standard Model backgrounds using early data will be summarized in this talk. Finally we show the expected discovery potential of SUSY particles and inclusive measurements of the SUSY mass scale with the integrated luminosity of just 0.1-1 fb^-1. The ATLAS detector has good potential to discover SUSY particles even in the early stage of collision.