Experiments of a Ma5 fix-geometry two-dimensional ramjet inlet with mixed-compression are conducted in a hypersonic wind tunnel. The results show that: under cruising condition, when the throttling ratio increases, at the exit of the inlet, the back pressure ratio rises, the Mach number decreases and the total pressure recovery coefficient declines firstly and rises then. The power spectrum of the dynamic pressure signals in the duct generally has no obvious peak value. When the throttling ratio is equal to 72%, buzz occurs in the inlet. The base frequency of the buzz is about equal to 48 Hz. As the throttling ratio decreases, the base frequency of the buzz declines and the terminal shock reaches the intake when the buzz ends. With a further decrease of the throttling ratio, the terminal shock firstly locates at the internal compression section and then enters the divergent section.