Objective To evaluate the value of ultrasonic elastography for diagnosis of chronic nonspecific low back pain. Methods From March to September, 2016, 32 patients diagnosed as chronic nonspecific low back pain and other 32 healthy people (controls) were measured lumbar erector spinae with ultrasonic elastography, and calculated Yang's modulus. The correlation between Yang's modulus and Visual Analogue Scale (VAS) or Japanese Orthopaedic Association (JOA) score in the patients were investigated with Pearson's analysis. Re-sults There was no significant difference in Yang's modulus between bilateral lumbar erector spinae in both the patients and the controls (t<1.849, P>0.05), but it was more in the patients than in the controls (t=9.931, P<0.001). The Yang's modulus was positively correlated with VAS score in the patients (r=0.614, P<0.001), but not with the JOA score (r=-0.243, P=0.180). Conclusion Ultrasonic elastography can be applied to differentiate low back pain from the healthy, and measure the intensity of pain.