We study the structure of imaginary Verma modules induced from the "natural
" Borel subalgebra of a toroidal Lie algebra. In particular, we establish a
criterion of irreducibility for imaginary Verma modules and describe their
submodules and irreducible quotients. We also describe the structure of Ve
rma type modules in the case of sl(2)-toroidal Lie algebra over two variabl
es.