The purpose of this study is to describe the effects of students' spatial abilities and the characteristics of students' spatial ability in completing geometry tasks through learning interventions that emphasize spatial activity. This study employs a one-group pretest-posttest design. The research subjects were 33 grade VIII junior high school students. The learning process highlighting spatial activities was developed through three phases: initial investigation, prototyping, and assessment. Results show that students predominantly trusted in the physical features of spatial objects, i.e. the shape and positions also used the help of real objects as a reference for abstract concepts and took advantage of hand gestures when conducting spatial activities. Through intervention, students were trained to recognize spatial objects through their position, form, size, and the mental movement of spatial objects to determine the shape from a particular perspective. Findings further exhibit that there are relations between spatial ability and language ability. This research is relevant for teachers and students in the learning process of geometry that focuses on spatial activities, with steps of information acquisition, facilitation of spatial activity, reinforcement, and integration of information.