Abstract: The high voltage tube tank of x-ray system is embodied by miniaturizing the portable x-ray system for better mobility and portability. The high voltage tube tank of portable x-ray system comprising of an xray tube for generating x-rays, a high voltage transformer for generating high voltage, a high voltage rectification circuit for transforming and boosting AC voltage to DC voltage, and a housing for storing the apparatuses thereof, is configured in such a way that the high voltage rectification circuit is comprised of multiple high voltage capacitors linearly aligned on both sides of the circuit board and the high voltage diode built between the confronting high voltage capacitors, wherein the x-ray tube is placed between the high voltage capacitors thereof.