Tone is one of the most important features of textual information in financial reports, that there are two views about managers' use of it: providing information (signaling) or impression management (opportunistic approach).This study analyze the relation between tone of board's activity reports and future financial performance of companies. Bag of words method have been used for measuring tone and two indicators (future ROA and future operating cash flow) have been used for measuring future financial performance. The sample of this study consists of 449 firm-years from 2009 to 2018 and Dynamic panel method  were used to test hypothesis. The result shows that tone of board's activity reports have negative effect on future ROA and future cash flow. These results provide probabilistic evidence about opportunistic use of tone in financial reports.