Laser　cladding　is　a　technique　in　which　a　laser　beam　is　used　as　the　heating　source　to　melt　the　alloy　powder　to　be　clad　on　the　surface　of　titanium　alloy　substrate.　Currently,　the　surface　of　many　titanium　alloy　components　needs　repairing　after　a　period　of　service　in　order　to　extend　their　service　life.　TiB　and　TiB2　are　considered　as　the　excellent　ceramic　reinforced　particle　for　their　compatible　physical　and　thermodynamic　properties,　high　hardness　and　Young＇s　modulus　of　elasticity.　The　intermetallic　compound　NiTi,　well-known　for　its　shape　memory　effect　and　pseudo-　elasticity,　is　one　of　the　rarely　few　intermetallic　compounds　having　excellent　combination　of　high　strength,　ductility　and　toughness　as　well　as　excellent　wear　resistance　and　fabrication　processing　properties.　An　insitu　TiB/TiB2　structured　ceramic　materials　as　the　reinforcing　phase　and　NiTi　intermetallic　phase　as　the　matrix　would　be　expected　to　have　an　outstanding　combination　of　high　hardness　and　toughness.　NiTi　alloy,　TiB　short　fiber　and　TiB2　particulate　reinforced　titanium　matrix　composite　coatings　were　prepared　by　laser　in　situ　synthesis　on　titanium　surface　with　different　ratios　of　Ni　powder　and　TiB2　powder　mixture　as　a　preset　level.　Synthesis　of　titanium　matrix　composite　coating　was　analyzed　by　XRD,　SEM　and　EPMA.　The　results　show　that　the　surface　quality　of　the　coating　increases　with　increasing　laser　power　density　and　the　amount　of　Ni　powder.　Whereas,　the　new　phase　of　NiTi2　and　coarse　diameter　of　TiB　short　fiber　are　found　in　the　coating　when　the　amount　of　Ni　added　is　improved.　The　reaction　mechanism　is　discussed　based　on　thermodynamic　calculations.　The　reaction　driving　force　size　to　Ni3Ti＞NiTi2＞NiTi＞TiB　order　arrangement　are　found　by　thermodynamic　calculation,　and　reaction　mechanism　of　competition　between　the　different　elements　is　discussed　based　on　phase　variation　of　the　type　and　content　in　the　coating.