Sm1-xPrxCo5　(x=0-0.6)　nanoflakes　with　CaCu5　structure　were　successfully　prepared　by　surfactant-assisted　high-energy　ball　milling　(SAHEBM).　The　crystal　structure　and　magnetic　properties　of　Sm1-xPrxCo5　(x=0-0.6)　nanoflakes　were　studied　by　X-ray　diffraction　and　vibrating　sample　magnetometer.　Effects　of　Pr　addition　on　the　structure,　magnetic　properties　and　coercivity　mechanism　of　Sm1-xPrxCo5　nanoflakes　were　systematically　investigated.　XRD　results　show　that　all　the　nanoflakes　have　a　hexagonal　CaCu5-type　(Sm,　Pr)(1)Co-5　main　phase　and　the　(Sm,　Pr)(2)Co-7　impurity　phase,　and　all　of　the　samples　exhibit　a　strong　(00l)　texture　after　magnetic　alignment.　As　the　Pr　content　increases,　remanence　firstly　increases,　then　slightly　reduced,　while　anisotropy　field　(HA)　and　H-ci　of　decrease　monotonically.　Maximum　energy　product　[(BH)(max)]　of　the　flakes　increases　first,　peaks　at　24.4　MGOe　with　Pr　content　of　x　=　0.4,　then　drops　again.　Magnetization　behavior　analysis　indicate　that　the　coercivity　mechanism　is　mainly　controlled　by　inhomogeneous　domain　wall　pinning,　and　the　pinning　strength　weakens　with　the　increased　Pr　content,　suggesting　the　great　influence　of　HA　on　the　coercivity　of　flakes.　(C)　2016　Author(s).