Background: Nowadays, most of the work styles are sitting down to work. Long-term sitting, poor posture and lack of exercise habit contribute to muscle guarding and pain. Sport climbing is different from traditional core training and specific training emphasizes posterior chain. Furthermore, sport climbing promotes the core strength and the trunk mobility. Therefore, through sport climbing, the specific training transfers from abdominal muscle to posterior chain. It enhances trunk core muscles, provides stable support for your cervical spine and remains in neutral position to your spine. Then, it reduces poor posture as a result of pressure leading to pain in the lumbar spine. Consequently, it promotes self-perceived health and physical function as well as health-related quality of life. Purpose: To study the effect of eight-week sport climbing for long-term sitting whether it strengthens core muscles or not Methods: This is a randomized controlled trial. The 30 long-term sitting people who have not regular exercise habit or do not exercise divided into sport-climbing group (n=15) and control group (n=15). The parametric　measurement was by means of core stability test, ultrasound (Titan, Sonosite), Quality of Life Scale-SF36 Standard Version, Oswestry Disability Index (ODI), Oswestry LBP disability questionnaire and trunk muscular endurance test, when compared between pre-and post-testing. It gave pre-and post-testing in eight-week sport climbing. Furthermore, it utilized paired-samples t test to analyze the variation within subgroup. In variation between subgroup, it showed variation of post-testing to pre-testing. Finally, a one-way analysis of variance was a way to test the variation between subgroup whether it made sense of statistical variation. Results: There were 30 long-term sitting people for this research. Twelve people finished sport plan and pre-and post-testing in sport-climbing group and there were fourteen people in control group. Four men and eight women were in sport-climbing group. The average age was 30.50±6.11 years old and the average height was 160.1±7.7 centimeter. Moreover, the BMI (Body Mass Index) was 21.99±3.60 with the average weight of 56.7±12.2 kg. In core stability test, after eight-week training, the AMT and the DLLT of sport-climbing group made sense of statistical significance. In side plank test and prone plank test, trunk muscle endurance of lateral trunk muscle in common usage had significant progress. In ultrasonic imaging, there was no significant difference between these two groups in transverse abdominal muscle and thickness or cross-section area of lumber multifidus. Quality of Life Scale-SF36 had significant progress only in health status of physical. However, ODI did not make sense of statistical variation. Conclusion: There were significant increases both in trunk muscle endurance and core stability for eight-week sport-climbing training. Therefore, sport climbing increased greater strength of core muscle more than general exercise.