In a pulse-modulated radio frequency atmospheric pressure dielectric barrier discharge in helium, the influence of the pulse width on the transition from a patterned glow discharge to a homogeneous glow discharge is experimentally investigated. The experimental results show that the discharge mode can transit from a patterned glow to a homogeneous glow at a moderate pulse width (7 μs) but only has a patterned glow at a short pulse width (4 μs) or a homogeneous glow at a long pulse width (18 μs). The characteristic regions of patterned and homogeneous glow discharges are also acquired. The results can be explained using the breakdown characteristics of the pulse-modulated radio frequency atmospheric pressure discharge.