Objective To explore the trajectory of medication adherence and its influencing factors in outpatients with new-onset hypertension, so as to provide a reference for developing targeted intervention.Methods A total of 337 newly diagnosed outpatients with hypertension were selected by convenience sampling method, then they were investigated by utilizing the Morisky Medication Adherence Scale (MMAS-8) at 4 weeks, 3 months, 6 months and 12 months after diagnosis.The group-based trajectory modeling was used to analyze the participants′ medication adherence trajectory, and its influencing factors were explored by utilizing multinomial logistic regression.Results There was no statistically significant difference in the participants′ scores of MMAS-8 at 4 time points (P＞0.05).The medication adherence trajectory was divided into three categories:a continuous high adherence group (52.82%), a moderate fluctuation group (37.09%) and a continuous low adherence group (10.09%).Multivariate logistic regression analysis showed that, compared with the continuous high adherence group, the patients with an age of 51-60 years old and taking three kinds or more medications were more likely to enter into the moderate fluctuation group (both P＜0.05), and the patients with an age of 36-50 years old, educational background of junior college, and per capital monthly income of the family less than 1 000 yuan were prone to enter into the continuous low adherence group, and social support was conducive to improving patients′ medication adherence ( all P＜0.05).Conclusion The medication adherence trajectory in outpatients with new-onset hypertension shows relatively stable characteristics within the first 12 months after diagnosis, but it reveals significant group heteroge-neity.Medical staff should pay special attention to those patients with continuous low medication adherence and fluctuating adhe-rence, and take targeted interventions according to the influencing factors, so as to improve their medication adherence.