Recently, user participatory workshops have been applied as a way to plan landscape spaces that reflects the needs and demands of the users. It is also required to improve the quality of the FECC (Forest Experience Center for Children), which is growing rapidly. Therefore, the purpose of this study is to deduct the design elements (forest play activities and space), the basic needs, and the demands of users in making the FECC a preschooler participatory workshop. For this, materials for preschooler participation were selected, and a step-by-step workshop was conducted to satisfy the demands of the preschooler's development. First, in the pre-workshops phase, design elements standards were deducted through the preschooler participatory results (41 children aged 6 and 7, Kindergarten). Second, in the main workshop phase, the design elements to be introduced on the site (Songsan-mulbit FECC) were deducted through the participating preschooler's selection and those results were analyzed. The materials used at the preschooler participatory process were 'drawing a picture' in the pre-workshop phase, and the design elements and the standard types charts were the forest play activity pictogram chart, and the forest play space general images chart in the main workshop. As for results, frst, there are 38 standard types of forest play activities that have been deducted. It consists of 27 cognitive activities (functional 16, constructive 4, symbolic 4, game on rule 3), 9 games (sensory 5, other 4), and two social play activities (solo, group). There are 21 standard types of forest play spaces. They consist of 8 play facility spaces (5 facility, 3 natural), 2 water spaces, and 11 spaces of 5 types. Second, as a result of applying the results to the site, the forest play activities to be introduced on the site were selected, and the functional play was most selected. Additionally, climbing and water play were most selected as the unit activities. Also, functional, constructive, symbolic, games based on rules were selected, even in the preschooler's development play. In the case of the forest play spaces to be introduced in the site, the preschooler's selection results by sex and age tended to be similar to the preschooler's comprehensive selection results, but the boys preferred function and adventure spaces more than the girls, while the girls preferred rest spaces more than the boys. This result is similar to the previous study results, which directly observed the preschooler's forest play behavior, and analysis that the preschooler recognized the site and selected the design elements introduced on the site. Therefore, the participatory workshop process and the materials process in this study are analyzed and applied to the purpose of the study. It is valuable as a case to be applied in design of the FECC from this point forward.