Green fluorescent protein (GFP) is an attractive reporter for bioprocess monitoring. A fluorescence-based method was developed to quantify GFP levels in transgenic plants and protein extracts. In this study, GFP was produced and secreted from suspension cells derived from transgenic rice. The RAmy3E promoter placed before the GFP gene controlled by sugars such as sucrose. The effects of sucrose concentration on the secretion of GFP and total protein into the medium were investigated in batch suspension culture. It was possible, therefore, to induce the expression of the GFP by removing sucrose from the cultured media or by allowing the rice suspension cells to deplete sucrose catabolically. The dry cell weight (7.06 g/L) and GFP level were detected as highest at 12%, 3% sucrose after 20 day culture, respectively. However secreted GFP fluorescence at the other sucrose concentrations (6%, 12%, 18% and 24%) were a little amount in media.