The Gamma-ray Burst Polarimeter―POLAR is a high sensitive detector which is dedicated to the measurement of Gamma Ray Bursts (GRB) polarization with a large effective detection area and a large field of view(FOV), which will contribute to the catch and measurement with high sensitivity of the transient sources like GRBs. There are different ways of measuring the GRB’s polarization according to the physical processes for different wavelengths of the photons. In the energy range from tens of keV up to a few MeV, the Compton scattering dependence on the photon polarization is usually applied. The detection energy range of POLAR is 50 keV∼500 keV. Based on the Compton scattering method, POLAR can be used for measuring the polarization of GRB prompt emissions with low Z material Plastic Scintillators(PS), Multianode Photomultipliers(PMT) and multi-channel ASIC Front-end Electronics(FEE). POLAR is an international collaboration project involving China, Switzerland, France and Poland, and is expected to be launched into the space around 2014 onboard the Chinese space laboratory “Tiangong-2(TG-2) With the support of National Natural Science Foundation of China(NSFC )and the Knowledge Innovation Program of the Chinese Academy of Sciences, a qualification model (QM) of POLAR has been developed in China, while the flight model(FM) of POLAR is now under of construction.