The gold hollow nanospheres have been synthesized by sacrificE-template method and the obtained sample has been characterized by TEM, SEM and XRD. The amperometric formaldehyde gas sensor was assembled with gold hollow nanospheres as the active electrode material and 1 mol/L KOH solution as electrolyte. The equation of linear regression(y=16.63x+4.063×10-7, r=0.9989)between the oxidation current(y(A))and the concentration of formaldehyde(x/(mol/L)) was obtained at the formaldehyde concentration in the range of 0 to 2.23×10-6 mol/L. The sensitivity of the sensor with gold hollow nanospheres as active material increased by about 70% compared with the sensor made of nanoparticles which had the same gold-loading in the work electrode, this method exhibits an advantage of decrease in the cost of the noble metal. This kind of sensor shows potential application in formaldehyde gas detection in this range due to its excellent sensitivity, stable response and good linear relationship.