In this work, a photoamperometric glucose biosensor based on glucose oxidase (GODx) was developed in flow injection analysis (FIA) system using ZnS-CdS quantum dot (QD) modified multiwalled carbon nanotube/glassy carbon electrode (ZnS-CdS/MWCNT/GCE). Cyclic voltammograms of the proposed electrode (GODx/ZnS-CdS/MWCNT/GCE) showed a pair of well-defined reversible redox peak attributing that direct electron transfer between the protein and electrode. The current of the reduction peak became more cathodic in the presence of O-2 due to the electrocatalytic activity of the electrode towards the reduction of dissolved O-2, but reduction current shifted to a less negative value upon addition of glucose in the solution. The obtained CV currents were affected by the irradiation of the electrode surface. Thus, the photoelectrochemical biosensing of glucose in the FIA system was studied by monitoring of the changes in the electrocatalyzed reduction peak current of dissolved O-2 at the proposed electrode dependent on glucose concentration. The proposed photoelectrochemical FIA method has a linear response to glucose ranging from of 0.01 to 1.0mM with detection limit of 3.0 M under optimized conditions. Photoelectrochemical biosensor was successfully fabricated in FIA system for selective, sensitive and repeatable detection of glucose and has been satisfactorily applied to determination of glucose in real sample.