Abstract. In this paper, we study some homological and cohomological properties of Banach algebras for some l`p-matrix algebras, say LMpI (C). We give enough and sucient condition that LMpI (C) has a central approximate identity. Then we characterize pseudo-contractibility of LMpI (C). We prove that, for each non-epty index set I; LMpI (C) is pseudo-amenable. Also we turn our attention towards amenability, approximate biprojectivity and approximate bi atness of `p-upper triangular algebras.
