In some cases, the extracellular concentration of potassium ions cannot be regarded as being constant. The potassium lateral diffusion leads to extracellular accumulation of potassium ions and the generation of potassium diffusive coupling. The effect of potassium diffusive coupling on spiral wave is investigated by using the Luo-Rudy phase I cardiac model with potassium diffusive coupling. The numerical results show that when the strength of potassium diffusive coupling is relatively strong, the potassium diffusive coupling makes extracellular potassium ion concentration rise first and then regularly oscillate, leading to the irregular meandering of spiral wave. It is observed that the width of spiral arm and the frequency of spiral wave decrease as the strength of potassium diffusive coupling increases. Thus, when the strength of the potassium diffusive coupling is strong enough, the potassium diffusive coupling can eliminate spiral wave and spatiotemporal chaos.