Objective To observe axial length， refraction and morphology in formdeprivation myopia （FDM） with genetransferred tissue inhibitors of metalloproteinase （TIMP2） in guinea pigs. Methods Sixty fourweekold guinea pigs in this experimental study were randomly divided into 4 groups： TIMP2 group， empty plasmid group， saline group and control group. A FDM model was established in the right eye by using a translucent plastic occluder. The left eye of the TIMP2 group was considered as the selfcontrol group. Genetransferred liposome， empty plasmidtransferred liposome and saline were injected in the first 3 groups， respectively， on the 15th day of deprivation. Refraction， axial length and the scleral structure were observed on 2， 7 and 14 days after injection. Data were analyzed using twoway analysis of variance. Results On 2， 7 and 14 days after injection， the average amounts of myopia in the TIMP2 group were -0.4±0.5 D， 0.9±0.6 D and 1.2±0.6 D. The differences for the day 14 were statistically significant compared to the other 3 groups （q=5.78， 5.34， 6.07， P<0.05）. Compared with the control group， the differences of day 2， 7， 14 were statistrcally significant （q=13.09， 9.72， 6.93， P<0.05）. On 2， 7 and 14 days after injection， the axial lengths of the experimental group were 7.78±0.04 mm， 7.69±0.03 mm and 7.65±0.03 mm. The differences on days 7 and 14 were statistically significant compared to the control groups （q7=5.51， 4.43, 4.82， q14=5.36， 4.78， 5.16； P<0.05）. The collagen fibrillar diameters of the sclera in the posterior segment of FDM eyes were found to be distinctly bigger and the space between the fibers was smaller than that of the control eyes. The average diameters of the fiber in the TIMP2 group were 49.7±6.8 nm， 71.3±6.0 nm and 97.8±10.4 nm， respectively， 2， 7 and 14 days after injection. The differences on day 7 and 14 were statistically significant compared to the the other 3 groups （q7=30.70， 12.30， 12.20， q14=21.80， 21.50， 21.20； P<0.05）. Compared with the control group， the differences of day 2 were statistically significant （q=14.40， P<0.05）. Conclusion The ectogenic gene of TIMP2 has an inhibitory effect on the changes in the biology and morphology in formdeprivation myopia of guinea pigs.