Strong　affinity　of　palladium　to　hydrogen　needs　to　be　overcome　in　the　rational　design　of　highly　efficient　and　robust　Pd-based　catalyst　for　hydrogen　evolution　reaction　(HER).　In　this　work,　we　achieved　the　insertion　of　boron　atoms　in　the　Pd　lattice　interstitial　sites　by　a　facile　co-reduction　method,　and　successfully　prepared　Pd-B　nanoparticles　supported　on　carbon.　Benefiting　from　the　optimization　of　electronic　state　induced　by　the　control　of　interstitial　boron　atoms,　the　obtained　Pd86B14/C　catalyst　exhibit　pronounced　alkaline　HER　performance　with　a　small　overpotential　of　38　mV　at　10　mA　cm(-2)　and　a　low　Tafel　slope　of　36.6　mV　dec(-1)　in　1　M　KOH.　Theoretical　calculations　unveil　that　the　inserted　boron　atoms　into　host　palladium　leads　to　the　charge　redistribution　and　the　lower　d-band　center　on　Pd　because　of　the　electron　transfer　between　Pd　and　inserted　B.　More　importantly,　the　control　of　inserted　boron　atoms　makes　the　d-band　center　of　Pd　appropriately　shift　negatively　relative　to　the　Fermi　level　and　consequently　balances　the　hydrogen　adsorption/desorption　behavior　of　Pd　surface,　resulting　in　superior　catalytic　performance　(Pd86B14/C).