Neural　stimulators　design　should　take　safety　as　the　top　priority　and　many　methods　have　been　developed　in　order　to　achieve　biphasic　charge　balancing　in　biphasic　stimulation　with　interphase.　Based　on　a　widely-used　neural　stimulation　configuration　and　two　electrode-electrolyte　interface　models,　this　work　gives　the　quantitative　analysis　of　the　voltage　change　on　the　electrode-electrolyte　interface　in　each　stimulation　phase　and　explores　the　causes　of　charge　imbalance　in　the　whole　biphasic　stimulation　process　especially　with　an　interphase　delay.　The　parameters　analysis　in　this　paper　is　beneficial　to　the　designers　for　improving　the　safety　of　neural　stimulators.　©　2021,　Springer　Nature　Singapore　Pte　Ltd.