Using friable embryogenic callus(FEC) of Dimocarpus longan Lour.cv.Honghezi as the material,we carried out the proteomic analysis of its growth processes by using the immobilized pH gradients two-dimensional electrophoresis technology and matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF/TOF).The results showed that:(1)The total protein was from 400 to 800 during longan FEC development,and it showed a rising trend in general although its variation trend had in fluctuation.Isoelectric point of all proteins was distributed between 4 and 7.Molecular weight of proteins of FEC during the normal development in longan was within 14-97 kD.The protein expression quantity was at relatively high within 30-66 kD,but within 30-45 kD it showed a rising trend and within 45-66 kD it showed a reverse trend.(2)Sixty-six proteins related to longan FEC development were identified.28.79% of the proteins were unknown identity or function,30.30% of the proteins participated in stress response and anti-oxidation,10.61% of the proteins were involved in energy and carbohydrate metabolism,10.61% of the proteins belonged to protein synthesis related,6.06% of the proteins were structural proteins involved in cytoskeleton remodeling,4.55% of the proteins were regulatory proteins,3.03% of the proteins were enzymes involved in nucleic acid metabolism.Additionally,1.52% of the proteins were associated with signal transduction and PCD,1.52% of the proteins were related to amino acid metabolism,1.52% of the proteins were lipid metabolism-related protein,and 1.52% of the proteins attached themselves to vitamin metabolism.(3)In the early stage(10-20 d),the expression of redox proteins associated with FEC in longan(including ascorbate peroxidase R147,R158 and HC21,phenylcoumaran benzylic ether reductase homolog TH6,glutathione peroxidase and peroxidase L26) was high,while the expression of peroxidase 4 was in late stage(40-50 d).Protein synthesis-related proteins showed a expression peak within 20 d,besides protein isoform 1 within 30 d.Different energy-associated proteins expressed more abundantly during whole period.There were S-adenosylmethionine synthetase(the enzyme related to precursors of polyamine) and a large number of peroxidase expression at the later stage of longan FEC development.It explained that the polyamine has not only the function like peroxidase for scavenging active oxygen,but enhance the activities of antioxidant enzymes.