A helical pile consists of a single or multiple bearing plates and the axis; and is a kind of a rotate penetration pile penetrated into the ground by rotation to support the structure. The rotate penetration pile is a type of displacement pile: the surrounding soil is displaced when installing the pile, and the pile can exert a large bearing power and pullout force. In addition, it uses displaced soil method that does not generate slime, and its applications are increasing in foreign countries owing to the environmentally friendly characteristics such as small noise and vibration. The need of rotate penetration pile, which is eco-friendly and can be constructed with relatively small equipment, is growing according to the increase in the numbers of piling in downtown area and structure remodeling projects. However, mostly driven piles-which are directly driven to the ground, and bored pile- pre-fabricated piles are buried to prebored underground, are used; however, rotate penetration piles still have limited use. Some of the reasons are: the lack of pile construction equipment; lack of domestic ground applications of the rotate penetration piles; and uncertain behavior characteristics of the weathered soil, etc. Particularly, the domestic study is limited on the weathered soil that is utilized as most of the stiff layers. Because most of the laboratory tests have been carried out until now to identify the support behavior after installation of piles and ground construction, the evaluating the support behavior is lacking due to the rotation intrusive process of the rotate penetration piles. Therefore, this study used indoor experiments simulating rotation intrusive process in weathered soil, to evaluate the bearing power behavior for the weathered soil, varying the diameter of the bearing plates, bearing plate spacing, number of the bearing plates, and bearing plate specifications. As the outcome of this study, the helical pile bearing power evaluation results, change in bearing power in accordance with main specifications, and review on the comparative analysis with the existing theories were provided.