Infected　people　are　isolated　to　minimize　the　spread　of　pandemic　diseases.　Therefore,　the　factors　related　to　self-isolation　(SI)　should　not　be　neglected,　and　it　is　important　to　investigate　the　factors　leading　the　infected　(or　possibly　infected)　people　to　choose　to　self-isolate.　In　this　paper,　we　tried　to　show　that　the　theory　of　planned　behavior　provides　a　useful　conceptual　framework　for　SI　when　facing　a　pandemic　risk,　and　a　regression　method　with　Chinese　provincial　(Guangdong　Province)　data　was　applied　to　investigate　how　attitude　(ATT),　subjective　norms　(SN),　and　perceived　behavioral　control　(PBC)　influence　SI　when　facing　a　pandemic　emergency.　The　results　and　the　robustness　tests　confirm　that　ATT,　SN,　and　PBC　have　a　significant　positive　influence　on　SI　when　facing　a　pandemic　emergency.　ATT　plays　the　most　important　role,　followed　by　SN　and　then　PBC.　Based　on　the　factors　of　SI,　we　found,　through　theoretical　and　empirical　analyses,　at　least　three　important　aspects　that　local　governments　need　to　consider　to　encourage　citizens　to　self-isolate　when　facing　a　pandemic.　©　2019　by　the　authors.　Licensee　MDPI,　Basel,　Switzerland.