<qa>  How many subjects would be collected and devided into two groups?It is consisted with two sub research. First,clinical research to know the effect of acupuncture for chronic low back pain will be processed with acclate, randomized, patient, outcome-assessor masking. 130 subjects would be collected and devided into two groupsExperimental and placebo. Experimental group will undergo with real acupunture treatment twice a week, for 6 weeks and acupuncture spots would be selected for each person by clinical specialist. Placebo group will undergo with Park-sham needle and same 8 acupuncture spots would be used for all subjects also twice a week, for 6 weeks. The effect will be accessed by VAS, x-ray, ODI, SF-36, EQ-5D, BDI before and the last treatments. 