Flow and heat transfer of a novel turbine shroud with throttle chamber under two kinds of orifice arrangements were numerically studied.The original shroud model composed of the impingement holes,film holes and jet channel.The two modified models have identical geometrical spacing except for the number and location of the orifices in the upper plate of the throttle chamber added in the jet channel.Different pressure values were set at the outlets of different row film holes simulating the mainstream favorable pressure gradient.The ratios of inlet total pressures of impingement holes to outlet static pressures of the third row film holes ranged from 1.6 to 3.6.The Nusselt number distributions were validated by the experimental data.The main target of this study was to quantify the impact of the throttle chamber on the flow regulation and intal heat transfer characteristics.The flow factor,relative mass flow rate,the Nusselt number and the heat transfer factors on the target walls were presented.It is found that the mass flow rate distributions in the film hole rows become more reasonable by the modification of location and number of the orifices on the throttle chamber.The throttle chamber decreases the heat transfer on the target walls.