<p>The present study aimed to determine the effects of the number of players on the playing style of junior high school students in small-sided games (SSG). The participants were 40 young male soccer players (age: 12.73 ± 0.63 years). The number of SSG players was set at 3 vs. 3 + 2 goalkeepers (GKs), 4 vs. 4 + 2 GKs, and 5 vs. 5 + 2 GKs, and the attacking play was measured using notational analysis. Statistical analysis was performed by unpaired t-test and χ² test. 3 vs. 3 had more passes to the GK than 4 vs. 4. Additionally, the occurrence rate of “dribbling” in the process leading to shooting was higher than 5 vs. 5. 4 vs. 4 had a higher occurrence rate of “forward direction” passing than 3 vs. 3. 5 vs. 5 had a higher number of passes and consecutive passes than 3 vs. 3 and 4 vs. 4. Also, the occurrence rate of “one-touch” in the process of shooting was higher than in 3 vs. 3. These results propose that 3 vs. 3 is characterized by individual goal scoring and GK’s participation in the attack, 4 vs. 4 is characterized by forward passing, and 5 vs. 5 is characterized by goal scoring with passing as a team.</p>