This paper presented a design of an x-ray-detector using CMOS image sensor. The main components consist of CMOS sensor, taper fiber optic, and image intensifier screen, CMOS sensor offers various advantages including miniaturesized, low power consumption and cost effective. CMOS-based digital camera becomes hence very demanding due to its potential application in multimedia and information technology. To apply the CMOS sensor as x-ray detector, x-ray-to-visible light convector is required. Our key component of x-ray-tovisible light converter is an image intensifier screen mounted on the wider end of taper fiber optic. The narrow end of the taper fiber optic is coupled on the half-inch CMOS image sensor. In order to get higher image quality and system flexibility, more versatile CMOS image-sensor controller are preferable. Such complicate designs are made possible by the creation of entirely VHDL reconfiguration and programmable components- the socalled Field programmable Gate Array (FPGA). The designed x-ray-detector with CMOS sensor camera has been tested to capture a bony structure and ap-plied for calcium measurement. The result is very promising. © 2006 IEEE.