Introduction: This research was to study the effect of positive induced emotions on happiness and depression after lingering induced arousal worry. Method: To study the effect of emotion induction (Positive and negative) on decreasing previously induced anxiety, 32 female students at high school grade 1 in Isfahan City, were randomly selected and then questionnaires of depression, happiness, MMPI 2 (Personality multiple questionnaire) and two scales of the big five factorial questionnaire (extraversion-introversion) was completed by them. Then they were randomly assigned into four groups (two experimental groups and two control groups) for the first group a sad film, the second group a cheerful film and the third group a neutral film was shown and the fourth group remained without intervention. Next day, all group members completed the depression and happiness questionnaire again. Research findings were analyzed using covariance and MANOVA analysis. Results: Those who turned their attention to cheerful film were happier than those who saw either the neutral and sad film or non intervention and those who saw sad film were more depressed than others. Conclusion: Positive emotion is more effect on negative emotion like depression and happiness. This effect called the undoing effect of positive emotions.