Timeline-based editing provides nonprofessional users an intuitive and friendly way for multimedia authoring, but the schedule-based and deterministic property of timeline results in the lack of the ability for supporting non-deterministic temporal behavior, which is one of the key features of SMIL2.0. This paper presents our elaborate effort of supporting non-deterministic temporal behavior by timeline-based editing. The concept of Dividable Dynamic Timeline (DDTL) is proposed in the paper, which includes two novel features: dividable timeline and dynamic section. With DDTL, authors can create interactive multimedia presentations while enjoying the convenience of timeline. Mechanisms of converting from DDTL editing results to SMIL2.0 and the reuse of SMIL2.0 scripts are presented in the paper. By the reuse of existing SMIL2.0 scripts and the flexible features of DDTL, an efficient and friendly authoring environment for SMIL2.0- based interactive multimedia presentations can be provided. Implementation of the system provides a friendly WYSIWYG environment and multiple views/windows are provided by the systems to help SMIL2.0 authors compose multimedia presentations efficiently.