An object of the present invention is to provide a black paste composition suitable for use in laser direct imaging devices employing a light source emitting a laser having a maximum wavelength of 350 to 420 nm, useful in forming a high-definition black matrix pattern efficiently, and superior in storage stability, a black matrix pattern formed by using the composition, a plasma display having the pattern, and a method of forming the black matrix pattern by using the composition. An alkali development-type black paste composition of the present invention comprises (A) a carboxyl group-containing resin, (B) a glass frit, (C) a black pigment, (D) a compound having at least one radically polymerizable unsaturated group in its molecule, and (E-1) an oxime-based photopolymerization initiator represented by the following general formula (I).