Objective To develop a modified lentiviral expression system of mCherry-GFP-LC3B,driven by the hematopoietic-specific SFFV(spleen focus-forming virus)promoter,in order to perform an efficient and real-time monitoring of autophagy flux with in terminally differentiated erythroid cells.Methods The lentiviral plasmid pRSC-SFFV-mCherry-GFP-LC3B was constructed and packaged into lentiviruses for infection of human erythroid progenitor cell line(HUDEP-2)and mouse fetal liver-derived primary erythroid cells.Autophagy dynamics of the cells were then analyzed using fluorescence imaging,Western blot,and flow cytometry in serum starvation and chloroquine inter-vention models.Results The SFFV promoter rendered significantly higher reporter expression efficiency than CMV promoter in HUDEP-2(97%vs.60%)(P＜0.01)and in the primary mouse erythroid cells(83%vs.1%)(P＜0.001),without disrupting normal erythroid differentiation.Serum deprivation increased au-tolysosomes(red puncta),elevated LC3-Ⅱ/LC3-Ⅰratios,and decreased p62 levels.Chloroquine treatment in-duced autophagosome(yellow puncta)accumulation(P＜0.001),showing a dose-dependent inhibition of auto-phagy flux(r2=0.92).Conclusions The SFFV-driven dual-fluorescent system enables robust and real-time mo-nitoring of autophagy flux in erythroid cells,providing a sensitive tool for mechanistic study of erythroid differenti-ation and related disorders such as anemia.