The purpose of this study was to determine whether there is an effect of modification of the traditional crank game on gross motor development in children aged 5-6. This research approach uses quantitative research with the type of research Quasi-Experimental Methods with One group Pretest-Posttest. Collecting data in this study using observation and documentation aimed at children to strengthen data about the effect of modification of the traditional crank game on children's gross motor skills. From the data analysis, it is known that there is an increase in children's fine motor skills which can be seen from the pretest observations which get an average score of 28.50% in the Underprivileged (KM) category and posttest which get an average score of 51.30% in the Capable category (M). The results showed that there was an effect of college on gross motor development in children aged 5-6 years.