Based on frontogenesis function, the frontogenesis and frontolysis of Kunming quasi-stationary front (KQSF) in early 2008 is diagnosed using high resolution (0.125°×0.125°, 6-h interval) reanalysis data of ERA-Interim. The role and contribution of each component of the frontogenesis function is also analyzed. Typical processes analyzed long-term maintenance of the front from January to February of 2008, the strengthening and westward advance of the front from January 20 to 27 of 2016 and the weakening and eastward retreat of the front from January 14 to 20 of 1979. Results indicate that diabatic heating has little effect on the frontogenesis and frontolysis of KQSF, but it exhibits a significant diurnal change. Under the influence of radiation, frontogenesis phenomenon occurs in the daytime and frontolysis phenomenon occurs in the nighttime. During the westward movement of cold air mass, the topography on the plateau generally uplift the cold airmass. However, the air mass can also descend due to local terrain forcing, which leads to frontogenesis due to the effect of vertical motion tilt. Since the terrain remains unchanged, the local frontogenesis mentioned above produces a secondary frontogenesis belt, which is closed related to the KQSF activities, including its formation, maintenance and swing. Horizontal convergence-divergence term and horizontal deformation term make primary contributions to frontogenesis. The major effect of shear deformation in the horizontal deformation term mainly causes frontogenesis, while the effects of the expansion deformation term are opposite in meridional and zonal directions. Its zonal effect causes frontogenesis, and its meridional effect causes frontolysis.