Anterior and posterior intervertebral gap of lumbar spine is important when developing the spinal implants regarding lumbar system. However, the measuring methods continue to be still controversial because of the absence of a standardized measurement. The objective of this study is to propose novel methods of measuring lumbar intervertebral gap and to conduct comparative analysis with other measuring methods. We took the lateral radiography images of 20 males taking the postures of supine, seat and standup. The anterior intervertebral gap and posterior intervertebral gap were measured with three different methods and two pre-existing methods. The comparison of results from three different measuring methods and two pre-existing methods showed that the difference at the anterior intervertebral gap was mostly statistically significant. This study suggests that it is necessary to consider the clinical meaning of the difference among measuring methods in order to establish a database to fabricate spine implants and to make efforts to improve measuring methods in the future.