As we know that the x-ray apparatus show the important role in the fundamental diagnoses. Due to its complete importation from foreign, however, the price of which is rather expensive, resultion in the deficiency of the apparatus for the districe hospital. Futhermore, the importation of which results in the negative imbalance of trade to foreign which is the national problem. Based on the three factors, economical, medical, and technical factors, the 300-mA x-ray apparatus which have only the radiographic technic are designed and constructed for the distritt hospital. The apparatus, providing the maxinum tube voltage of 100 kVp, the maximum tube current of 300 mA, and 20 steps of exposure time settings,contain three units that are control unit, high-tension unit, and x-ray tube. The construction of the control unit employs the appropriate technology, thereby being easy to construct, maintain,and repair and having the resonable cost of construction, maintenance, and repair. For the high-tension unit, because of having little time to study the thesis, we need to have the experienced technicians in our country deal with the construction. For the x-ray tube, the technology used in the consturction is too high for our country to deal with. It is thereby, imported from foreign, including its housing. Including the cost of consturction of the machanic tasks, such as the tube stand, the table, etc., and the cost of labor, the total cost of consturction of the x-ray apparatus is of about 200,000 Bahts which is two times less than that from foreign. The rather-high cost of costruction is due to the expensive price of the x-ray tube which is almost one third of the total cost. The accuracy tests and operating tests give the acceptable and satisfactory results.