This study aims to determine the effect of the traditional game of jemamok (bebentengan) on improving biomotor abilities in students of SMA Negeri 1 Belalau with game models and modifications. The method in this research is experimental research with a research design of One Group Pretest Posttest Design. The subjects in this study were students of SMA Negeri 1 Belalau class XI, totaling 20 samples taken using the Simple Rundom Sampling technique and only using one group. The implementation stage in this study was given a pretest to determine the initial data from students using a test instrument from several biomotor components, namely agility, power, speed. Then after the pretest , it was continued by giving treatment using the jemamok game (bebentengan) which was held for 12 meetings with game modifications and finally the posttest out to find out changes in the final results that occurred after giving treatment. The data analysis technique used the t test through the prerequisites for normality and homogeneity. The results of the t-test obtained that the t value of the agility effect was 2.454 and the t table was 1.686 with a significance level of 0.019 > 0.05. Furthermore, for the t value of calculating the effect power is 1.171 and t table is 1.686 with a significance of 0.577 > 0.05. Then the last one was obtained the t value for calculating the effect of speed was 1.586 and t table was 1.686 with a significance of 0.121 > 0.05. So it can be concluded that there is an effect of the traditional game of jemamok (bentengan) on the improvement of the biomotor agility, power, speed of the students of SMA Negeri 1 Belalau.

Keywords: Traditional Games, Biomotor Improvement