Cognitive training for persons with mild cognitive impairment (MCI) has become a hot topic. However to date it remains controversial whether persons with MCI can really benefit from cognitive intervention. We aim to further investigate this by using meta-analysis of seventeen clinical studies of cognitive intervention for MCI. The results demonstrate that after training, patients with MCI improve significantly both in overall cognition and overall self-ratings. Specifically, persons with MCI obtain moderate benefits in language, self-rated anxiety and functional ability, and receive mild benefits in episodic memory, semantic memory, executive functioning/working memory, visuo-spatial ability, attention/processing speed, MMSE, self-rated memory problem, quality of life, activities of daily life and self-rated depression. The results also suggest that persons with MCI benefit from the cognitive intervention in the follow-up data. The present meta-analysis demonstrates that cognitive intervention can be a potential efficient method to enhance cognitive and functional abilities in persons with MCI, although the improvements may be domain-specific.