Workflow adaptation is an important task of workflow reuse. During semantic workflow adaptation based on workflow streams, i.e., the reusable segments of semantic workflows, the absence of workflow streams structurally similar to the streams of the retrieved semantic workflow in the workflow streams repository leads to unachievable workflow adaptation. Focusing on the problem, this paper proposes an improved method, i.e., an adaptation algorithm of semantic workflows based on behavioral characteristics of workflow streams. The set of task adjacency relations is used to express the workflow streams' behavioral characteristics. First, for each stream of the retrieved semantic workflow (called query stream), the data index of the anchor set and stream matching rules are used to filter the workflow stream repository to obtain the matching stream candidates.Then, these stream candidates are verified with the change request and the behavioral similarity metric, to obtain the query streams that need to be substituted and the corresponding matching streams that are most coincident with the change request and behaviorally similar to them. Next, each matching stream is used to substitute the query stream in the retrieved workflow to gradually adapt defects of retrieved workflow. Finally, the adapted semantic workflow is obtained. The experimental results show that the proposed adaptation algorithm achieves the adapted semantic workflow set with higher overall quality and has better adaptability compared with existing adaptation algorithm based on workflow streams. The adaptation algorithm can provide semantic workflows of higher quality for business processes managers for references when adapting workflows to meet new business requirements, and is helpful for the improvement of the efficiency and quality of workflow reuse in business process management (BPM).