Beam　characteristics　of　a　linear　phased　array　transducer　are　critical　to　its　engineering　applications　as　well　as　to　its　design.　This　paper　proposes　a　method　for　the　theoretical　calculation　of　ultrasound　field　radiated　by　a　linear　phased　array　coupled　to　an　elastic　solid　by　a　longitudinal　wave　couplant.　In　this　case,　the　ultrasound　field　can　be　determined　by　superposition　of　the　exact　and　analytical　solutions　of　transient　elastic　waves　induced　by　a　number　of　discrete　line　sources　normally　acting　on　an　elastic　half-space.　Based　on　the　theoretical　calculation,　this　work　investigated　the　influences　of　several　important　parameters　in　a　linear　array　transducer,　such　as　wave　length,　array　size,　ratio　of　element　width　to　inter-element　spacing,　to　the　ultrasound　field　characteristics.　Interesting　phenomena　and　useful　results　are　obtained,　which　provide　fast　and　accurate　guidance　for　linear　phased　array　transducer　design.　It　also　satisfies　diverse　and　specific　demands　for　actual　engineering　testing　using　arrayed　transducers.　(C)　2017　Published　by　Elsevier　B.V.