 Current Minimally Invasive THR includes: 1 Minimally Invasive Two-Incision THR MIS-2, 2 Minimally Invasive Modified Watson-Jones THR MIS-WJ. In contrast, mini-incision utilizes smaller incision 10 cm in definition to perform the THR which can further be divided into mini-anterolateral Mini-AL and mini-posterolateral Mini-PL.The purpose of this study is to investigate how MIS THR can affect the results of THR by a prospective randomized clinical trial. It is hoped that some new standards could be established for the total hip replacement surgery. 