Objective To observe the effect of electroacupuncture（EA） at back-shu points of five zang on fatigue status

quality of life and motor cortical excitability in patients with chronic fatigue syndrome（CFS）

so as to explore the possible mechanism of EA for CFS. Methods A total of 72 patients with CFS were randomized into an EA group（36 cases

4 cases dropped off） and a sham EA group（36 cases

3 cases dropped off）. In the EA group

EA at Ganshu（BL 18）

Xinshu（BL 15）

Pishu（BL 20）

Feishu（BL 13） and Shenshu（BL 23） was adopted

with continuous wave

2 Hz in frequency. In the sham EA group

sham EA at non-acupoints（1.5-2.0 cm lateral to back-shu points of five zang） was applied

with shallow needling

and no current was connected. The treatment in the both groups was 20 min each time

once every other day

2 weeks as one course

3 courses were required. Before and after treatment

the scores of fatigue scale-14（FS-14） and the MOS 36-item short form health survey（SF-36） were observed

and cortical excitability（the resting motor threshold [RMT]

amplitude of motor-evoked potential [MEP-A] and latency of motor-evoked potential [MEP-L]） was detected in the two groups. Results After treatment

the physical fatigue score

mental fatigue score and total score of FS-14

as well as RMT of motor cortex in the EA group were decreased compared with those before treatment（P<0.01）

the physical fatigue score and total score of FS-14 in the sham EA group were decreased compared with those before treatment（P<0.05）; each item score and total score of FS-14 and RMT of motor cortex in the EA group were lower than those in the sham EA group（P<0.01

P<0.05）. After treatment

each item score and total score of SF-36and MEP-A of motor cortex in the EA group were increased compared with those before treatment（P<0.01）

which were higher than those in the sham EA group（P<0.01

P<0.05）. Conclusion EA at back-shu points of five zang can effectively improve the fatigue status and quality of life in patients with CFS

its mechanism may be related to the up-regulating excitability of cerebral motor cortex.