Let S be a uniformly locally finite semi group. We study approximate biprojectivity of l(S) . We also show that for the Clifford semi group S; if l(S) is approximately biprojective, then l(S) is pseudo amenable. We characterize approximate biprojectivity of Segal algebras and weighted group algebras. A class of non-approximately biprojective triangular algebras related to semigroups is given.