Lectins are (glyco)proteins which bind specifically carbohydrates or glycoconjugates being useful tools in widespread aplications. In this work, pure Parkia pendula seed lectin (PpeL) was structurally evaluated under different glucose concentrations, variations of temperature and pH values, as well as urea treatment. Lectin conformational changes were then evaluated by fluorescence spectroscopy and zeta potential measurements. All evaluations were carried out with PpeL concentration of 100 mg/ml in 0.15 M NaCl. PpeL was evaluated at different glucose concentrations (0-0.5 M). Thermal stability was approached by incubating PpeL at distinct temperatures (20 to 90°C) during 20 min. The lectin was submitted to different pH values (pH 2.0 to 9.0) and distinct urea concentrations (0.1 to 6.0 M), by 4 h and 25°C. After each assay, fluorescence measurements (excitation wavelenght at 280 nm) were performed using a Spectrofluorimeter PC1, ISS, USA, with a quartz cuvette (path length: 1 cm²). Zeta potential measurements were followed by electrophoresis using a Zeta-sizer (Nano ZS90, Malvern).  Fluorescence measurements indicated that PpeL tryptophan residues are situated in a highly hydrophobic environment; probably the residues are not involved with carbohydrate binding. The spectrum did not reveal alteration after glucose addition. PpeL abrupt conformational changes occurred at 60 °C. The lectin was more compact at pH 2.0; above pH 8.0 PpeL was totally denatured. Above 4 M urea, tyrosine and tryptophan residues were separated, suggesting a separation of lectin dimers. In conclusion, fluorescence spectroscopy detected changes in the conformational structure of PpeL; the zeta potential confirmed alterations of PpeL surface charges after treatments.