Delayed and non-union of the femur shaft fractures in adult have been increased in spite of improvement of method of treatment. In geheral, the principal factors predisposing to delayed and non-union have been known as infection, disturbances of the blood supply, poor immobilization (inadequate rigid fixation), distraction of fracture site. 43 cases of the femur shaft fractures in adult over 18 years old examined at the department of orthopedic surgery, Korea General Hosipital, during the period of January 1973 to January 1982, were divided into two Groups; Group A was 31 cases, which had been taken solid bony union as control group and Group B was 12 cases, which had been developed delayed and non-union. Group A and B were analysed to find out other etiologic factors such as liver function which were suspicious to result in delayed or non-union of the fracture except above mentioned principal factors. The results were as follows, l. In delayed and non-union group (Group B), the interval of age was 20 to 40 years of age, open fracture was 33.4% comparing to control(6.5%), comminuted fracture was 83%, comparing to control (42%), the time interval to operation was delayed over 2 weeks(18%) comparing to control(8%g), and gap between fractured ends after internal fixation was more than 2mm in 33% comparing to control(absent), and liver function, especially, SGOT, and SGPT was bad in 46% comparing to control(13.4%). 2. All 3 cases ot infection in fracture site were in delayed and non-union group, tracture level, associated injury and postoperative immobilization were not concerned with delayed and non-union between two groups.