A defibrillation system includes an electrode set to contact a biological subject, and a portable electronic device supporting mobile wireless communications and coupled to the electrode set. The portable electronic device includes a processor and a memory unit. The memory unit stores program instructions which, when executed by the processor, enables the processor to obtain an electro-cardiac signal of the biological subject through the electrode set, and output a discharge command according to the electro-cardiac signal for delivering an electrical shock to the biological subject through the electrode set.
