In this paper,we describe the educational practices of algorithm using learning support system with visualization of program behavior.The systems visualizing behavior of program have certain effect to understand algorithm behavior.Introducing them into a classroom of algorithm is expected to allow learners to cultivate better understanding.However,almost all of the systems cannot incorporate the teachers intent of instruction that may be chose to suit the learners among several instructions.Moreover,the teacher needs to devise the contents of class when the teacher want to teach the property of algorithms with those systems,such as the number of comparisons or swaps.Based on these considerations,we conducted classroom practices of algorithm incorporating the system that we developed in our previous work.Our system visualizes the target domain world according to the visualization policy defined by the teacher.In addition,we included the contents based on discovery learning about the properties of algorithm in the practices.In this paper,we describe the overview of our educational practices and the reactions of learners.Furthermore,we show that the framework in our practices can be established in algorithm classes.