  We study the hypernuclei of C and B isotopes by Hartree-Fock model with
Skyrme-type nucleon-nucleon and nucleon-hyperon interactions. The calculated
$\Lambda$ binding energies agree well with the available experiment data. We
found halo structure in the hyperon $1p$-state with extended wave function
beyond nuclear surface in the light C and B isotopes. We also found the
enhanced electric dipole transition between $1p$- and $1s$-hyperon states,
which could be the evidence for this hyperon halo structure.
