The laminar interaction of counterstreaming plasmas in the presence of a magnetic field was studied by numerical simulation. The model is one‐dimensional and is based on the Vlasov equation with straight orbits for ions(&OHgr;i t ≪ 1). Electrons are treated as a massless, zero‐termperature fluid maintaining charge neutrality with the ions, and a finite resistivity is assumed. Magnetic field and density profiles are determined for different Mach numbers, density ratios, and resistivities. Effects of various finite initial density profiles in the streaming plasma are investigated. The distribution function is examined to determine whether microinstabilities would develop in a turbulent model. The relevance of these results to the formation of magnetic pistons is discussed.