Abstract: Objective: To test the stiffness of continuous multilevel thoracic vertebra in goats immediately after implanting hemiepiphyseal compression staples and evaluate the stability of fixed segments by biomechanics. Methods: Six fresh specimens of thoracic vertebrae（T6-T11） from 6 goats（age 2-3 months） were divided into three groups: native,single（one staple was implanted spanning each disc continually）,and double（two staples were implanted spanning each disc continually）.With each group,the stiffness of fixed segments during left and right rotation,left and right bending,flexion and extension were tested. Results: During left and right rotation,the stiffness in segments with single and double staples was not significantly different from that in native segment（P＞0.05）.During left and right bending,flexion,extension,the stiffness in segments with single and double staples was decreased as compared to that in native segment（P＜0.05）. Conclusion: In vitro,the immediate stability of fixed spinal segments is lower than that in normal thoracic vertebra in the goat.