Abstract: QCD multijets events are a main background in different searches. Due to the large uncertaities in their theoretical calculation, the Monte Carlo simulation is not able to predict the correct shape and amount of the background surviving the cuts. A data driven method is proposed to predict the QCD contribution to our signal which is SUSY events with at least one top quark in the final state. The first results from applying the method on the real data is shown. A short report is given about the CMS and LHC status and my contribution in Data Quality Monitoring for Hadron Calorimeter.