Objective Study on the clinic value of the application of two-dimensional and three-dimensional sonography on observing the fetal facial structure. Methods Applying Voluson 730 three-dimensional probe surface imaging mode and two-dimensional probe to make sonography on 16～48 weeks fetus in 1805 cases, emphasized on observing the fetal facial structure, saving the image information, making three-dimensional reconstruction and comparing the result of post partum and the result after induction of labor. Results In 1805 cases, applying two-dimensional and three-dimensional sonography to observe the facial structure of the fetus of 23～35 weeks, the display rate is 93.1% and 95.1% respectively, and there is no obvious difference between the two modes. The three-dimensional is higher than two-dimensional for the fetus less than 23 weeks, with the display rate 69.6% and 84.8% respectively, and the two-dimensional is a bit higher than three-dimensional for the fetus more than 35 weeks, with the display rate 90.4% and 88.7% respectively. One cleft lip case is excluded. Conclusion As long as mastering the optimum examination time and operation skill, there is no obvious difference between the display rate of two-dimensional and three-dimensional sonography on observing the fetal facial structure, the two modes can be complementary in the work to improve the accuracy of the diagnosis and be favorable for the prepotency.