Five compounds previously known structures, scopoletin (1), northalifoline (2), stigmast-4-en-3-one (3), tiliroside (4), and oplopanone (5) were obtained from the flower buds of Magnolia fargesii using chromatographic separation methods. The structures of 1-5 were identified by the interpretation of their spectroscopic data including 1D- and 2D-NMR as well as by comparison with reported values. Three compounds 1-3 were found from M. fargesii for the first time in this study. All the isolates (1-5) were subjected to in vitro bioassays to evaluate the inhibitory activity on advanced glycation end products formation and rat lens aldose reductase (RLAR). Compound 1 showed a remarkable inhibitory activity on advanced glycation end products formation with $IC_{50}$ value of 2.93 ${mu}M$ (aminoguanidine: 961 ${mu}M$), and showed a significant RLAR inhibitory activity with $IC_{50}$ value of 22.5 ${mu}M$ (3.3-tetramethyleneglutaric acid: 28.7 ${mu}M$). Compound 4 exhibited potent inhibitory activity against RLAR ($IC_{50}$ = 14.9 ${mu}M$). In the further experiment ex vivo, cataractogenesis of rat lenses induced with xylose was significantly inhibited by compound 1 treatment.