Spikelet proteins expressed at the young microspore stage in rice were separated and analysed by two-dimensional polyacrylamide gel electrophoresis (2DE). The separated proteins were electro blotted onto a polyvinylidene difluoride (PVDF) membrane, and 50 proteins were analyzed by a gas-phase protein sequencer. The N-terminal amino acid sequences of 20 out of 50 proteins were determined. N-terminal regions of the remaining proteins could not be sequenced because of blocking. The internal amino acid sequences of proteins were determined by sequence analysis of peptides obtained by the Cleveland peptide mapping method. Results revealed the presence of the photosynthetic apparatus at rice young microspore stage. Major proteins identified in this study could be used as a marker for various studies on physiological stresses.