Stearic　acid　(SA)　as　a　phase　change　material　(PCM)　can　solve　the　problem　of　solar　energy　mismatch　in　time　and　space.　However,　the　low　thermal　conductivity　limits　its　development.　To　improve　the　thermal　conductivity　of　SA　in　thermal　energy　storage　systems,　a　novel　SA/boron　nitride　(BN)　composite　PCM　was　prepared　by　melting　the　blending　method.　Different　physical　parameters　were　measured　to　assess　the　comprehensive　performance　of　SA/BN.　SA/BN　thermal　properties,　microstructure,　crystal　structure,　and　chemical　stability　are　characterized　using　different　instrumentation.　Results　demonstrated　that　the　prepared　SA/BN　shows　a　lower　melting　temperature　and　a　higher　solidification　temperature　compared　to　SA.　Meanwhile,　when　the　loading　amount　of　SA　is　88　wt%,　the　crystallinity　and　melting　enthalpy　was　84.36　%　and149.34　J　center　dot　g(-1).　The　thermal　conductivity　of　SA/BN　is　2.82　times　higher　compared　to　pure　SA,　which　is　0.96　W　center　dot　m(-1　center　dot)K(-1).　Furthermore,　SA/BN　displays　excellent　cycling　stability　and　thermal　stability,　the　melting　and　solidification　enthalpy　changed　by　2.89　%　and　2.18　%　for　50　cycles.　The　weight　loss　of　SA/BN　occurs　between　200　and　350　degrees　C,　which　means　that　the　SA/BN-12　is　suitable　for　building　heating.