A microarray carrier assembly including a scan tray and a plurality of microarray blocks detachably disposed on the scan tray is provided. The scan tray includes a frame including an opening and a slot, and a transparent substrate covering the opening of the frame. Each of the microarray blocks includes a main body, a probe array distributed on the main body and facing towards the transparent substrate of the scan tray, and a plurality of guiding pins disposed on the main body and surrounding the probe array, wherein a top surface area of the guiding pin opposite to the main body is less than a bottom surface area of the guiding pin connected to the main body, and the guiding pins are detachably inserted into the slot of the frame of the scan tray.