Accumulation of reserve materials in filling grains involves coordination of different metabolic and cellular processes, and understanding the molecular mechanisms underlying the interconnections remains a major challenge for proteomics. Rice is an excellent model for studying grain filling because of its importance as a staple food and the available genome sequence database. Our observations showed that embryo differentiation and endosperm cellularization in developing rice seeds were completed approximately 6 days after flowering (DAF); and thereafter, the immature seeds mainly underwent cell enlargement and reached the size of mature seeds at 12 DAF. Grain filling began at 6 DAF and lasted until 20 DAF. Dynamic proteomic analyses revealed 396 protein spots differentially expressed throughout 8 sequential developmental stages from 6 to 20 DAF, and determined 345 identities. These proteins were involved in different cellular and metabolic processes with a prominently functional skew toward metabolism (45%) and protein synthesis/destination (20%). Expression analyses of protein groups associated with different functional categories/subcategories showed that substantially up-regulated proteins were involved in starch synthesis and alcoholic fermentation; whereas the proteins down-regulated in the process involved in central carbon metabolism and most of the other functional categories/subcategories such as cell growth/division, protein synthesis, proteolysis and signal transduction. The coordinated changes were consistent with the transition from cell growth and differentiation to starch synthesis and clearly indicated that a switch from central carbon metabolism to alcoholic fermentation may be important for starch synthesis and accumulation in the developmental process.