X-ray radiation produced by a small gas puff Z-pinch device in Tsinghua University was detected. This device was powered by a 16 mF capacitor bank charged to 230 kV, corresponding to a storage energy of 4.3 kJ, the discharge current reached its peak value of 210 kA at a time of 2.5 ms. The X-ray radiation from a Neon gas puff Z-pinch was measured with a sub-ns rise time PIN detector. The differential signal of discharge current was recorded to determine the pinch point, when the X-ray radiation was emitted. The signals were analyzed and discussed in this paper.