Abstract: Experimental results that delay and self-assessment of prospective memory in present research contradict with each other. This paper adopted a word-detect prospective memory task which was inlaid in some self-confident assessment items. The frequency of the target word increased across trials. The result indicated that: (1) A short delay between prospective memory instructions and background activity will lower the prospective memory performance. But in the period of 7-57 minutes(7 min, 17min,27min, 37min, 57min) prospective memory maintained. This result supported the suggestion that prospective memory forgetting may occur only during the first minutes after the encoding of intention; (2) There is no significant correlation between prospective memory and retrospective memory, so do some other variables like, sex, intelligence, and personality(16 indices of 16PF and 4 indices of Eysenck). (3) Correlation between prospective memory and retrospective monitor is significant, while nonsignificant relationship is found for self-assessment; (4) Age greatly influences prospective memory and self-assessment, children are overconfident and the elder are not so good as the young both in self-assessment and performance

Key words: prospective memory, retrospective memory, self-assessment, retention interval