Elliptic flow allows us to probe early dynamics in high energy nuclear collisions. The υ 2 result of charged hadrons and identified hadrons [1,2] from 200 GeV Au+Au collisions at RHIC suggest that the matter with partonic collectivity and thermalization has been formed in central collisions. In this analysis, we present preliminary results of υ 2 for K S 0 and Λ from 200 GeV Cu+Cu collisions. The partonic collectivity and thermalization assumption are tested in smaller Cu+Cu system comparing with those from Au+Au collisions...
