The　passive　Q-switching　performance　of　an　Yb:LaCa4O(BO3)(3)　crystal　laser　was　investigated　for　the　first　time　to　our　knowledge.　Stable　repetitively　pulsed　laser　action　was　demonstrated　with　a　2D　MoTe2　saturable　absorber　under　high　output　couplings　ranging　from　70%　up　to　95%.　A　maximum　pulsed　output　power　of　2.11　W　was　produced　at　a　repetition　rate　of　357　kHz,　with　a　slope　efficiency　of　32%　in　terms　of　incident　pump　power.　The　largest　pulse　energy,　minimum　pulse　duration,　and　highest　peak　power　achievable　were,　respectively,　6.6　mu　J,　103　ns,　and　52.4　W.　Our　work　suggests　that　this　relatively　new　monoclinic　oxyborate　crystal　may　be　more　advantageous　over　most　of　other　Yb-ion　materials　in　making　high-energy　pulsed　lasers　passively　Q-switched　with　2D　saturable　absorbers.