[en] The EAST superconducting tokamak is an advanced steady-state plasma physics experimental device to be completed successfully at the Institute of Plasma Physics, the Chinese Academy of Sciences (ASIPP). The engineering design incorporates the superconducting toroidal field (TF) and poloidal field (PF) magnets, the vacuum vessel, the thermal shields, the cryostat and the current leads. The cryostat of EAST Tokamak is a large single walled vessel surrounding the entire Basic Machine with central cylindrical section and two end enclosures, a flat base structure with external reinforcements and dome-shaped lid structure. The main function of EAST cryostat provides the thermal barrier with the base pressure of 5 · 10^-4 Pa between the ambient temperature testing hall and the liquid helium cooled superconducting magnet. The base structure was connected with the main support which has eight equally spaced support legs anchored on concrete base. The loads applied to the cryostat are vacuum pressure, the dead weight of vacuum vessel, thermal shield, PFC and magnet which are totally about 360 tons, seismic events and electromagnetic forces driven by plasma disruption. It also provides feed through penetrations for all the connecting elements inside and outside the cryostat. The main material selected for the cryostat is stainless steel 304L. The structural analyses including buckling for the cryostat vessel under the plasma operation condition have been carried out using finite element code. Stress analysis results show that the maximum stress intensity was below the allowable limit, and that the cryostat vessel had buckling safety of over 16. Based on the results, structural robustness of the cryostat vessel has been proved. The engineering design has been finished and the fabrication started and completed in 2002 and 2004 respectively. The Chinese company, Shanghai Boiler Works, Ltd (SBWL) is responsible for manufacture of cryostat vessel. The dished lid was fabricated by using a set of head ramming machine and a set of head flanging machine (BOLDRINI) imported from Italy with working diameter from 1800 mm to 8000 mm.Two halves of cylinder rings for the fabrication of the cylindrical section are precisely bent to the required shape and carefully welded together to form the central cylinder section. Precious cutting of the holes for ports was performed by numerical control (NC) boring and milling machine tool after the previously rough cutting using plasma jet technique. The base is the flat bottom of 60 mm thickness with 16 H beams stiffened plate bolted to main support. The inside surface facing vacuum has eight vacuum vessel supports and sixteen TF-and-PF supports. Because the surfaces of supports on the base are datum planes, a number of surfaces and holes have to be precisely machined to provide accurate means for exact assembly. The base has been precisely machined by using NC manufacturing center to satisfy the design requirement. During the fabrication, the vibration stress relief (VSR) method was used to relief the residual stress formed by welding process. Vacuum tightness of the welds was checked by an integral helium leak test of each whole section. The contours of the sections were measured by optical measuring system and met well the given tolerances. The paper will summarize the structural analyses, the design activities and give a short description of the fabrication of the cryostat component. (author)