Abstract: 【Objective】 Determining basic metabolism and stress resistance response to short-day treatment at the protein level for Pinus tabulaeformis Carr. container seedling and providing theoretical basis for applying the short-day treatment on seedlings used in the difficult site afforestation in Northern China.【Method】Short-day treatment was applied to P. tabulaeformis container seedlings by artificially reduced day length to 10 hours for 21 days. Seedling leaves were sampled and leaf proteins were extracted by improved phenol method. A proteomic analysis using two-dimensional electrophoresis(2-DE)in combination with MALDI-TOF/TOF MS analysis was performed to investigate changes in protein expression. The MS/MS data were submitted to Mascot search engine to search the NCBInr and Swiss Prot database for protein identification. Functional information of the identified proteins was found in UniProt.【Result】We obtained five proteins expressed differentially(P < 0.05)induced by short-day treatment. They were up-regulated expression of oxygen-evolving enhancer protein 1(OEE1)(spot 404), glyceraldehyde-3-phosphate dehydrogenase(GAPDH)(spot 539), elongation factor Tu(EF-Tu)(spot 654), ribulose bisphosphate carboxylase/oxygenase activase(RCA)(spot 681), and down-regulated expression of phosphoglycerate kinase 1(PGK1)(spot 641). They are mainly involved in plant photosynthetic metabolism, sugar metabolism and stress defense.【Conclusion】The different expression of P. tabulaeformis seedling leaf proteins can be induced by short-day treatment. These proteins are mainly involved in plant primary metabolism and stress response, suggesting that short-day treatment could play important roles in the development of basic metabolism and stress resistance of seedling.