Degenerative Lumbar spinal stenosis (DLSS) is a major problem for public health and the primary reason the older seek lumbar spine surgery. Acupuncture is safe and maybe effective for DLSS but the evidence is poor. Therefore, an objective assessment of acupuncture efficacy is critical for making informed decisions about its appropriate role for patients. A total of 80 participants meet prior inclusion criteria will be recruited. The participants will be allocated to acupuncture group or placebo needle (unpenetrated acupuncture) group randomly. Twenty-four treatments will be provided over 8 weeks. The primary change of Modified Roland-Morris Disability Questionnaire (RMDQ) and secondary outcomes including the change of Number Rating Scale (NRS); the change of Self-paced Walking test (SPWT); the change of Swiss Spinal Stenosis Questionnaire (SSSQ); the expectations that acupuncture might help participants with DLSS. All outcomes will be assessed at baseline, and/or after 4, 8, 20 and 32 weeks. Statistical analysis will include independent sample t-test, Chi-squared test and non-parametric test. The investigators hope the result of this trial will clarify the value of acupuncture for DLSS and help clinicians make proper decisions.

Inclusion Criteria:

Participants who meet all of the following conditions will be considered for enrollment. The inclusion criteria are as follows:

1. Pain in the low back, buttock, and/or lower extremity with standing, walking and/or spinal extension. (Using NRS questionnaire to measure pain symptoms, and pain measured by NRS ≥ 4.)
2. Roland-Morris score of at least 7.
3. Mild-moderate-severe lumbar central canal spinal stenosis identified by MRI or CT scan.
4. Lower extremity symptoms consistent with neurogenic claudication.
5. Age 50 to 80 years old.
6. Signed the consent and take part in this trial of his/her willing.

Exclusion Criteria:

1. Congenital stenosis of vertebral canal, serious indications of DLSS (such as segmental muscular atrophy, bowel and bladder disturbances), spinal nerve root canal stenosis, lumbar spondylolysis, lumbar tuberculosis, lumbar vertebral tumors, and vertebral body compression fracture.
2. Spinal instability requiring surgery.
3. Severe vascular, pulmonary or coronary artery disease that limits ambulation including recent myocardial infarction.
4. Participants who have cognitive impairment that may render the subject unable to give informed consent or provide accurate data.
5. Clinical co-morbidities that could interfere with the collection of data concerning pain and function.
6. Acupuncture within the past 30 days.
7. Administered pain control drugs during the week prior to the baseline assessment (e.g.,non-steroidal anti-inflammatory drugs or herbal anti-inflammatory agents).

Individual participant data (IPD) will be preserved, when the paper submitted, if the journal ask IPD, it will be uploaded as a supplement.