This presentation will discuss the results of two laboratory studies to examine the roles of positive memory in anxiety and depression. In study 1, 155 grade 7 to 10 students completed a computerized item-method directed forgetting task to examine the intentional forgetting of emotional words. The results revealed that among teenagers with high depression level, greater anxiety was associated with less positive memory bias. In study 2, 168 grade 8 to 11 students participated in a 2-back task. Intrusive costs in reaction time, which represent the cognitive effort to inhibit irrelevant information and activate relevant information in the working memory updating process, were calculated respectively for positive, negative and neutral facial expression stimuli. The results showed that adolescents with higher anxiety sensitivity was related to lower intrusion cost in reaction times for irrelevant positive content. Results of the two experiments suggest that positive intervention to enhance positive memory may serve as a prophylactics to prevent development of anxiety and depression. Practical applications including a psychological gymnasium developed in correctional services in Hong Kong using positive intervention approaches to enhance positive memory will be discussed based on the above results.