The purpose of this paper is to discuss more effective method of mathematical problem posing by using computer. We practiced such mathematical activities by university students who were the prospective teachers. In study (I), we reported the practice of problem posing by using computer after solving original problem by using computer. We gave students enough time to create problems and assign students planning problems freely from the first. A feature of the method in this practice is to provide situations in which students make conjectures on results and get the numerical calculation by using computer. Students who tackled making problem by using computer were seemed to be interested in considering around various problems and get some deep understanding for the mathematical properties related to the problems. Some students showed much originality in their problems, which might not be made without using computer. We observed more positive learning activities than the usual classes. It is asserted that the making opportunity of problem posing by using computer planned freely from the first by students is very important, in particular for the prospective teachers.
