Background　Workplace　climate　is　a　great　significant　element　that　has　an　impact　on　nurses＇　behavior　and　practice;　moreover,　nurses＇　service　behavior　contributes　to　the　patients＇　satisfaction　and　subsequently　to　the　long-term　success　of　hospitals.　Few　studies　explore　how　different　types　of　organizational　ethical　climate　encourage　nurses　to　engage　in　both　in-role　and　extra-role　service　behaviors,　especially　in　comparing　the　influencing　process　between　public　and　private　hospitals.　This　study　aimed　to　compare　the　relationship　between　the　five　types　of　ethical　climate　and　nurses＇　in-role　and　extra-role　service　behaviors　in　public　and　private　hospitals.　Methods　This　study　conducted　a　cross-sectional　survey　on　559　nurses　from　China　in　May　2019.　The　questionnaire　was　distributed　to　nurses　by　sending　a　web　link　via　the　mobile　phone　application　WeChat　through　snowball　sampling　methods.　All　participants　were　investigated　using　the　Ethical　Climate　Scale　and　Service　Behavior　Questionnaire.　SPSS　22.0　was　used　for　correlation　analysis,　t-test,　and　analysis　of　variance　test,　and　Mplus　7.4　was　used　for　group　comparison　(p　＜　.05).　Results　The　law　and　code　climate　has　a　much　greater　influence　on　nurses＇　in-role　service　behavior　in　private　hospitals　than　on　that　in　public　hospitals　(beta　=　-　0.277;　CI　(95　%)　=　[-0.452,　-　0.075];　p　＜　.01),　and　the　instrumental　climate　has　a　stronger　influence　on　nurses＇　extra-role　service　behavior　private　hospitals　than　on　that　in　public　hospitals　(beta　=　-　0.352;　CI　(95　%)　=　[-0.651,　-　0.056];　p　＜　.05).　Meanwhile,　the　rules　climate　has　a　greater　effect　on　nurses＇　extra-role　service　behavior　in　public　hospitals　than　it　does　in　private　hospitals　(beta　=　0.397;　CI　95　%　=　[0.120,　0.651];　p　＜　.01).　Conclusions　As　the　relationship　between　the　five　types　of　ethical　climate　and　nurses＇　in-role　and　extra-role　service　behaviors　in　public　and　private　hospitals　were　different,　the　strategies　used　to　foster　and　enhance　the　types　of　ethical　climate　are　various　from　public　to　private　hospitals.　The　caring　and　instrumental　climate　are　the　key　to　promote　extra-role　service　behavior　for　nurses　in　private　hospitals.　And　the　independent　climate　has　a　great　effect　on　extra-role　service　behaviors　for　nurses　in　public　hospitals.