Aims: To determine the best fit model for students' academic writing motivation and self-regulation. Study Design:  Descriptive-causal design. Place and Duration of Study: The study was conducted among senior high school of Region XIII during 2021-2022. Methodology: The respondents were chosen using stratified random sampling. The data were collected using the online platform. Results: Results showed that the respondents had a high level active reading style; their vocabulary learning strategy was always visible; and their self-regulated learning was high. It also revealed that there was a linked between academic writing motivation and self-regulation. There was a significant relationship between active reading in academic writing motivation and self-regulation; between vocabulary learning strategy, academic writing motivation, and self-regulation; between self-learning, academic motivation and self-regulation. Likewise, there was a significant influence of active learning on academic writing motivation and self-regulation, vocabulary learning strategies and self-learning on academic writing motivation and self-regulation. Finally, model 5 was the most suitable for students’ academic writing motivation and self-regulation. Conclusion: There is a substantial association between students' academic writing motivation and self-regulation and active reading, vocabulary learning strategies, and self-learning. The best model for encouraging and regulating students' academic writing is Model 5. It implies that students needed to have motivated so that they are about to control their learning. This outcome serves as a reminder to teachers that in order for students to develop learning independence and trust, teachers must pique their interest in the lessons or classroom activities.