The possible effects of TV violence on regular television viewers have been a critical problem. Study results have supported that there is a positive relation between the amount of violence viewed on TV and viewers' aggressiveness. However, these are cases mostly in America or in Europe and it can possibly be said that, in Japan, there have been no studies to clarify the relation between them. Thus, one of the purposes of this study was to clarify the relation between the amount of violence viewed on TV and viewers' aggressiveness. 473 (249 junior high and 224 senior high school) students were asked to choose up to five programs from among 25 violent programs and to answer 20 questions about their daily violent bahavior. The result indicates that there is a positive relation between them. The second purpose of this study was to clarify the relationship between the violence viewed on TV and the viewers' degree of desensitization toward violent scenes. The author hypothesized that the more people watch TV violence the more they become used to it and are no longer upset by witnessing violence. Subjects were asked how they would react when they witnessed violent scenes. The result indicates that there is no positive relation between them. However, the data indicate that there is a positive relation only in the case of senior high school students. This may suggest that the more years people are exposed to TV violence the more they become used to it. The third purpose of this study was to verify the effects of different types of programs on viewers' aggressiveness and on the degree of desensitization towards violent scenes. The author referred to Iwao's three categories of violent television programs; random violence, purposive violence and passive violence programs. Subjects were asked what type of program they frequently watch and were categorized into three viewing types; random violence viewing, purposive violence viewing and passive violence viewing types. The relationship between the amount of violence viewed on TV and the degree of desensitization towards violent scenes was analyzed for each viewing type. The result indicates in each case, there is no positive relation between them. The relationship between the amount of violence viewed on TV and viewers' aggressiveness was also analyzed for each viewing type. The result indicates that for each type, there is a positive relation between them and especially in the cases of viewing random violence and passive violence, the relation is stronger than when viewing purposive violence.