〔Abstract〕 Objective To establish an experimental model of Turner′s tooth caused by trauma in SD rats and observe its surface by scanning electronic microscopes(SEM) and energy dispersive spectrometry(EDS) was performed. Methods 40 SD rats aged one day were randomly divided into four groups(n=10). The control group did nothing, The experimental group was exerted different perpendicular forces(per 5 mm2) on the mandibular anterior alveolar process, which was divided into 5 N force group, 10 N force group and 15 N force group. The SD rats were killed at 30 days old to observe the enamel development of their mandibular central incisors. Meanwhile, SEM and EDS were used to observe normal enamel area and enamel hypoplasia area. Results The control group: all teeth erupted; all enamels developed well. 5 N force group: all teeth erupted; the occurrence rate of enamel hypoplasia was 10%(2 teeth had enamel discoloration). 10 N force group: 1 tooth unerupted; the occurrence rate of enamel hypoplasia was 80%(12 teeth had enamel discoloration and 4 had enamel defects). 15 N force group: 7 teeth unerupted, the occurrence rate of enamel hypoplasia was 60%(3 teeth had enamel discoloration and 9 had enamel defects). There was a statistic difference in the number of unerupted teeth between group 10 N force group and 15 N force group(P<0.05). Under SEM, cracks and rough appeared on the surface of enamel. EDS showed that the Ca and P content in enamel hypoplasia was lower than that in the normal enamel area(P<0.05). Conclusion Tooth trauma can lead to enamel hypoplasia and unerupted teeth. The force of 10 N per 5 mm2is better to establish an experimental model of Turner′s tooth caused by trauma in SD rats. The surface enamel of Turner′s tooth caused by trauma is rough, uneven and the content of calcium and phosphorus decreases.