A　beryllium-free　nonlinear　optical　(NLO)　crystal　K3Ba3Li2Al4B6O20F　(KBLABF)　with　sizes　up　to　18　×　13　×　8　mm3　was　successfully　grown　by　the　top-seeded　solution　growth　method　using　LiOH-H3BO3-BaF2　flux.　The　key　limiting　factors　on　the　crystal　morphologies　and　sizes　were　carefully　analyzed.　Meanwhile,　by　using　the　minimum　deviation　technique,　the　refractive　index　dispersion　was　measured　and　fitted　well　by　the　Sellmeier　equations.　The　results　suggest　that　KBLABF　is　a　negative　uniaxial　crystal　with　moderate　birefringence　of　0.06050-0.06834　at　a　wavelength　range　from　363　to　852.1　nm.　Furthermore,　the　type-I　phase　matching　range　for　fundamental　(second　harmonic)　light　is　down　to　486　(243　nm)　in　theory,　which　indicates　that　KBLABF　crystal　could　achieve　532　and　266　nm　light　generation　by　direct　second-harmonic　generation.　As　compared　with　the　famous　NLO　crystals　β-BaB2O4　and　CsLiB6O10,　KBLABF　crystal　exhibits　a　smaller　walk-off　angle　and　larger　acceptance　angle　at　the　wavelength　of　532　nm　while　having　a　comparable　short　absorption　edge,　sufficient　birefringence,　and　moderate　NLO　response.　Furthermore,　in　contrast　to　highly　hygroscopic　CsLiB6O10,　it　is　nonhygroscopic.　These　attributes　make　KBLABF　a　promising　candidate　for　practical　applications　in　UV　light　generation.　©　2017　American　Chemical　Society.