Objective To explore the possible mechanism of Jisui Kang（JSK

脊髓康） in the treatment of spinal cord injury（SCI）. Methods Eighty SD rats were randomly divided into sham operation group

model group

prednisone group

and Jisui Kang group

with 20 rats in each group. Except for the sham operation group

the rats in the other groups used the modified Allen′s method to establish the acute SCI model. The spinal cord of the rats in the sham operation group were exposed but not injured. After modeling

rats in the sham operation group and model group were administered with 20 ml/（kg·d） normal saline by gavage

while rats in the prednisone group and JSK group received 60 mg/（kg·d） prednisone solution and 25 g/（kg·d） JSK solution by gavage

respectively. The outcomes were assessed at the 7 th

14 th

21 st and 28 th day after operation

with five rats at each time point. The motor function of hindlimbs determined by BBB score and oblique plate test were evaluated. After collecting the serum

the exosomes were extracted and identified by the exosome′s marker proteins（Tsg101

CD63

CD9）. The expression of RhoA

ROCK protein and mRNA in the injured area

and the expression of miR-21

miR-126

miR-133 b mRNA in exosomes were detected. Results Compared with the sham operation group at the same time point

the model group had significantly reduced angle of the oblique plate test and the BBB score at all time points

higher expression of RhoA protein and mRNA at the 7 th and 28 th day

higher expression of ROCK protein and mRNA at the 28 th day

and lower expression of miR-21

miR-126

miR-133 b mRNA in exosomes at the 7 th and 28 th day（P<0.05）. Compared with the outcomes in the model group at the same time point

the angle of the oblique plate test and the BBB score significantly increased at the 7 th and 21 st day in the JSK group and prednisone group; the expression of RhoA

ROCK protein and mRNA decreased at the 28 th day; and the expression of miR-21

miR-126

and miR-133 b mRNA increased in exosomes at all time points（P<0.05 or P<0.01）. Conclusion JSK may promote the expression of miR-21

miR-126

miR-133 b mRNA in serum exosomes of acute SCI model rats

thereby inhibiting the RhoA/ROCK pathway

repairing spinal cord injury and improving the motor function of rats. The effect works best at 28 days.