Objective To evaluate the desimetrie performances of Seven29TM two-dimensional ion chamber array(2D-array).Methods Seven29TM 2D-array was calibrated by using solid water,IBA Dose 1 dosimeter and RIT 113 film dosimetry system.Tests and verifications were performed to evaluate the preci sion of absolute and relative doses of the 2D-array in solid water.Meanwhile ,the dose linear and energy re sponse of the 2D-array were studied.Results Solid water was a good equivalent phantom of water.For 2D-array,the calibration factor in solid water was 1.007 ,the absolute dose error was less than 2.1% ,the rel ative dose error was less than 3.8% and the errors of dose linear and energy response were hess than 0.2% and 1.2% ,respectively.Conclusions The Seven29TM 2D-array,possessing excellent desimetry perform ances,is a powerful tool for intensity modulated radiotherapy.