This paper studied the dosimetry of patients with cervical cancer using three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiation therapy (IMRT). The doses of target areas and the organs at risk (OAR) were studied and analyzed in detail, which will give us a base for clinical choice of cervical cancer radiotherapy technology. Twenty cases of cervical cancer patients were selected randomly, aged from 38 to 65 and the median age was 46 years old. The CT images were obtained by CT and transmitted to the Oncentra planning system, delineated in the clinical target volume (CTV), planning target volume (PTV), and organ at risk(bladder, rectum, femoral head), and designed respectively 3D-CRT and IMRT plans. The prescription doses were 46.80Gy, fractionated doses were 1.8Gy. The PTV dose volume histograms (DVH) and isodose curve were used to evaluate the dosimetry of these two plans with the differences: (1) the conformity index(CI); (2) the homogeneity index(HI); (3) the maximum dose of distribute to the OAR such as bladder, rectum, left and right sides of the femoral head; (4) the percentage volume of the bladder, rectum, left and right sides of the femoral head under radiation at different dose levers. The results indicated that the conformity index of IMRT plans was distinctly superior to the 3D-CRT. IMRT plans distinctly reduced the volumes of the rectum, left and right sides of the femoral head by the high dose levels. IMRT plans had advantages in reducing the high dose area bladder and rectum, femoral head around the radiation volume of a 3D-CRT. It is concluded that patients with cervical cancer received IMRT may diminish the Normal Tissue Complication Probability (NTCP) and severity.