Nine compounds, caffeic acid, naringenin, apigenin, luteolin, kaempferol, verbascoside, isoverbascoside, isocampneoside II, and cistanoside F, were isolated from the EtOAc and n-BuOH fractions of P. coreana bark. The structures of these compounds (1-9) were elucidated by spectroscopic methods and literature data. All the isolates were subjected to in vitro bioassay to evaluate their inhibitory activity against rat lens aldose reductase. Among these, compounds 6 and 8 indicated the significant inhibitory activity on rat lens aldose reductase with $IC_{50}$ values of 2.67 and 5.59 ${mu}M$, respectively. Especially, The inhibition activity of acteoside was 3.9 times better than that of quercetin as a positive control (10.6 ${mu}M$). These results suggested that phenylethanoid glycosides are likely to be the potential compounds for the prevention and/or treatment of diabetic complications.