Objective　　To study the protective effect of cervical sympathetic block (CSB) on liver function and structure of severely burned rats and its possible mechanism. 　　Methods　　A rat model of severe burn (TBSA 20% Ⅲ) was induced by blocking bilateral cervical sympathetic nerves with 0.01% Ropivacaine. The rats were divided into control group

burn group and CSB group. Protective effect of CSB on liver function

antioxidation

Bcl-2 expression and pathologic change in liver tissue was detected. Its mechanism was studied by measuring blood pressure and blood perfusion volume in liver and hypothalamus.  　　Results　　The levels of plasma-albumin in CSB group were 48.98±6.89

38.61±4.35

24.05±3.62 and 22.57±4.10 mmol/L respectively 1

3

5 and 7 d after burn.  The levels of ALT were higher in CSB group (48.15±7.37

58.21±5.43

62.07±8.16 and 56.87±5.88 IU/L respectively 1

3

5 and 7 d after burn）than in burn group

（P0.01）. The hepatic T-AOC values were higher in CSB group (3.16±0.17

2.88±0.15

2.71±0.16

and 2.61±0.58 respectively 1

3

5 and 7d after burn) than in burn group（P0.01）. The blood pressures were more stable in CSB group (90.58±5.69

82.69±3.81

70.61±9.51 and 82.05±2.36 mmHg respectively 1

3

5 and 7 d after burn) than in burn group （P0.01）. The hepatic and hypothalamic blood flow volumes were higher in CSB group [0.302±0.041

0.284±0.024

0.16±0.023

0.256±0.03 ml/(min·g) and 1.013±0.113

0.721±0.110

0.944±0.438

0.765±0.316 ml/(min·g) respectively burned instantly

1

3 and 5 d after burn] than in burn group（P0.01）.The pathologic changes of liver structure were milder while the expression level of Bcl-2 in liver was higher in CSB group than in burn group. 　　Conclusion　　CSB can protect the liver of severely burned rats by regulating the hypothamus axis and sympathetic-kidney axis.