本文考虑初值是分片常数且间断线经过原点的一类二维非线性双曲型守恒律组．解包含一类新的波──称之为Dirac-接触波．本文给出了这种Dirac-接触波的熵条件，方程组的解可以视为上有界线性泛函.

A two-dimensional hyperbolic system of nonlinear conservation laws was considered for any piecewise constant initial data having two discontinuity rays with the origin as vertex. One kind of new waves, which was labelled as the Dirac-contact wave, appeared in the solution. The entropy conditions for the Dirac-contact waves were given. The solutions on the Dirac-contact waves can be viewed as the bounded linear functionals on C(R2×R+).