Strangeness measurements at LHC with ALICE

A review of the first results obtained on strangeness production in pp collisions at 0.9 and 7 TeV cm. energy with the ALICE detector at LHC will be presented. About 250,000 minimum bias events recorded in 2009 during the very first LHC runs at 0.9 TeV were analyzed. Preliminary results on central rapidity production of mesons containing strange quarks (K^±, K_s⁰, ϕ(1020)) as well as single and double strange baryons are reported. More than 400 million minimum bias events have been collected up to now at 7 TeV by the ALICE experiment. Using only a fraction of the collected events the signals of many strange mesons (K_s⁰), hyperons and resonances (K*(892)⁰, ϕ(1020) and Σ(1385)) have been extracted. The ϕ(1020) invariant mass and the raw yield of as a function of transverse momentum will be shown.