: The purpose of this study is basic data for developing baseball uniform in the future by carrying out a survey of amateur baseball players on the wearing pattern of uniform and inconvenient details. To do this study, a survey targeting 307 male social baseball players in their 20s to 40s was conducted, and a preliminary survey through interview with designers, MDs and patternmakers had also been carried out and analyzed prior to the main one. The result shows that armpit and back patches get wet with perspiration the most, and patches around knees are likely to be worn out because of frequent sliding. Thus, they are dissatisfied with poor protective function the most and need quilted pads around knees. Answers for a question on injuries during games indicates that shoulder injuries due to pitching or batting and abrasion owing to sliding are most common and knee injuries are also frequent. As for the wearing satisfaction of uniform, they want elasticity and breathability of textile to be improved; they are not satisfied with its design and fit because they think top and bottoms are much too long and uncomfortable; they often find dirt inside of the uniform during games. Besides, they find it very difficult to remove dirt from the uniform even after washing. There has been a growing population of amateur baseball players over recent years, so this study would help develop functionally improved uniform and be used for developing uniform for professional baseball players.

: This study develops baseball uniforms for amateur baseball players with excellent appearance and functional movement. This study selected a conventional baseball uniform and developed a new one for amateur baseball players with improved function and appearance based on previous research results. In case of developed baseball uniform materials, this study used polyurethane mixed fabric for the top to improve flexibility. A mesh material was used at the armpit, back, and bottom of the top, side line of pants and pockets to improve breathability. In addition, quilted material was added to the knee to improve durability and protection. For the patterns and design, this study used a gusset under the arm to assist in comfortable movement as well as reduced the length of the top and circumference of the hem to decrease unnecessary parts. For the pants, this study used a waistband gripper to avoid the top riding up, added darts behind the knees to bend comfortably, and added additional fabric inside the hem to prevent dirt. In addition, we reduced the width and length of the pants. Wearing evaluation was divided into appearance evaluation by experts and on-site-wearing test by baseball players. The wearing evaluation results for the developed baseball uniform indicated higher evaluations than a conventional baseball uniform in all sections as well as showed significant differences in all sections. The result of movement adaptability evaluation showed the highest satisfaction for 'the top does not ride up' and 'dirt do not get in'.