"Event anisotropy measurement in high-energy 
heavy-ion collisions at RHIC"

The event anisotropy is one of the information to 
undertstand the eary stage of the heavy-ion collisions 
where quark gluon plasma might be formed, there are 
several important observations reported from RHIC 
experiments. The low pT part of the measured elliptic 
flow parameter (v2) is well described by hydro-
dynamical picture, and the high pT part is considered 
as a result of the jet suppression, and the quark 
number scaling of the v2 is found in entire pT range. 
The single electron and the inclusive photon v2 
measurements would give information of flow of 
heavy quark and direct photon, respectively. 
The recent experimental results especially on the 
flow and its origin will be discussed.