Abstract: To investigate hypersonic boundary transition phenomena and provide reliable experimental data for CFD code validation,boundary layer transition experiments have been con-ducted at the hypervelocity ballistic range of China Aerodynamics Research and Development Center.The cone-cylinder-flare models are 105mm in length,flying at speed of 1.94km/s(Ma 5. 65),with unit Reynolds numbers of 4.32 ×10 7 ~1.20 ×10 8 m-1 .Images of transition and turbu-lent boundary layer are obtained with laser shadowgraph technique,resulting in measured turbu-lent boundary layer thickness of 0.6 ~2.2mm,and the dimension ratio of 0.3 to 0.8 between turbulent eddy and boundary layer thickness,which reduced along the flow direction.It is shown that,images of Ma 5.65 hypersonic boundary layer transition could be obtained by ballistic range experiments at given flight environment,in which the transition location,boundary layer thick-ness and turbulent eddy scale could be determined.