Objective Functional tricuspid regurgitation(FTR) levels can vary over time and its longitudinal changing patterns may predict right ventricular dysfunction(RVD) risk. We aim to identify different trajectories of FTR in those who received mitral valve replacement(MVR) and investigate the association between longitudinal trajectory groups and RVD risk in a cohort study. Methods and results A prospective cohort study, reported usual FTR levels at baseline in 2005–2015 and the participants of MVR have been followed up for 5~6 years, approximately every one years, and so far, the data have been collected across five subsequent phases. Five-year longitudinal trajectories of FTR were identified using group-based trajectory modelling(GBTM). We identified 3 distinct trajectories using a GBTM, labeled by initial value and changing pattern: stable group(258/378, 68.2%), increasing-slow group(67/378, 17.6%) and increasing-fast group(53/378, 14.2%). Treating the stable group as the reference, the age- and sex-adjusted odds ratio(OR) was 25.84 (95% confidence interval, 11.78-56.65) for the increasing-slow group and 139.94(95% confidence interval, 45.47-430.68) for the increasing-fast group by logistic regression model. After adjustment for every potential confounding factors, the OR is 14.21(95% confidence interval, 4.36-46.33)、49.34(95% confidence interval, 8.88-273.87) respectively. Conclusions The longitudinal trajectories of worsening FTR were mostly associated with increased risk of RVD outcomes, which is independent of other factors including FTR levels. These findings have implications for intervention and prevention of RVD among individuals who received MVR.