الملخص

Abstract A blocking set B in projective plane PG(2,q) is a set of points such that every line in the plane intersect B in at least one point and there exist a line intersect B in only one point, we say that B is minimal if B has no blocking subset. In this research we proved the non_existence of minimal blocking set of size (30) contains 12_secant and not contains 13_secant in PG(2,19).