The purpose of this research was to study effect of small-sided games training on heart rate (HR), blood lactate (BL) and rating perceived exertion (RPE). Twelve male futsal players age between 18-25 years were the subjects of the research. The participants were divided into 3 teams and completed two different pitch size of a small-sided games training (20x20 m. and 20x28 m.). The games consisted in 4x3 min. bouts interspersed with 3 min. active recovery and each games lasted 24-hour on separate occasions. HR was measured throughout the game. BL and RPE were recorded immediately after training. RPE using the Borg Scale (0-10 Scale). Data were statistically analyzed by mean, standard deviation and matched paired t-test. All testing used the 0.05 level of significant. The result showed the mean of HR and BL were significantly different between pitch sizes (p 0.05) (the 20x20 m. of training RPE = 4.3±0.7 and 20x28 m. training RPE =4.3±0.5). In conclusion, the pitch size 20x28 m. of training might be used for practice and give maximum benefit. (Journal of Sports Science and Technology 2014;14(1): 93 -104) KEYWORD: Small-Sided Futsal Games Training, Heart Rate, Blood Lactate, Rating Perceived Exertion