Based　the　idea　of　original　＇Ping-pong＇　protocol,　an　improved　＇Ping-pong＇　protocol　based　on　single-particle　and　Einstein-Podolsky-Rosen　(EPR)　entanglement　is　presented.　The　EPR　entanglement　is　used　to　detect　the　eavesdropping　and　the　single　particle　is　used　to　transmit　the　information.　During　the　protocol,　the　sender　Alice　transmits　an　EPR　entanglement　pairs　and　a　single　particle　to　the　receiver　Bob　at　the　same　time.　The　bit　error　is　caused　by　the　random　position　of　the　single　particle.　In　our　security　analysis,　an　eavesdropping　will　cause　at　least　a　bit　error　rate　of　16.7%,　and　the　probability　of　detecting　eavesdropping　with　bit　error　rate　is　50.0%.　We　also　give　a　simulation　which　is　based　on　law　of　large　numbers　and　Monte　Carlo　method.　In　our　simulation,　we　use　mean　square　error　(the　value　is　1.8115　×　10　-　5)　to　indicate　that　the　simulation　data　is　approach　to　the　theoretical　value.　Compared　with　the　original　＇Ping-pong＇　protocol,　the　presented　protocol　doesn’t　need　the　control　mode,　and　it　doesn’t　need　to　store　the　quantum　state.　©　ICST　Institute　for　Computer　Sciences,　Social　Informatics　and　Telecommunications　Engineering　2019.