Objective To assess the surgical and rehabilitation effects of total hip arthroplasty (THA) through comparing changes of gait parameters in patients before and after THA.MethodsThe gaits of 7 THA patients during their natural walking before THA and in the 25th week after THA were tested by using a portable gait analyzer (IDEEA, MiniSun, USA). The gait parameters including single limb support (SLS) time, double-limb support (DLS) time, SLS/DLS, stride length, foot fall strength were collected for statistic analysis by SPSS 16.0 and Excel 2010. Results The SLS of the healthy leg after THA significantly decreased (P<0.05); for the majority of THA patients, the SLS of the diseased leg decreased, the DLS and SLS/DLS of the healthy leg also decreased obviously, while the foot fall strength of the diseased leg increased after THA. Conclusions The SLS of the healthy leg can be used as a sensitive parameter to evaluate the operation effect of THA. The portable gait analysis system can quantitatively reflect the subject’s gait, thus it is a non-invasive and convenient method of evaluating the operation effect in clinic.