Electronic Journal of Differential Equations, Vol. 2003(2003), No. 94, pp. 1-22. Title: On nonnegative entire solutions of second-order semilinear elliptic systems Author: Tomomitsu Teramoto (Onomichi Univ., Hiroshima, Japan) Abstract: We consider the second-order semilinear elliptic system $$ \Delta u_i=P_i(x)u_{i+1}^{\alpha_i}\quad\hbox{in }\mathbb{R}^N, \quad i=1,2,\dots,m $$ with nonnegative continuous functions $P_i$. We establish nonexistence criteria of nonnegative nontrivial entire solutions for this system. We also proved a Liouville type theorem for nonnegative entire solutions. Submitted February 6, 2003. Published September 9, 2003. Math Subject Classifications: 35J60, 35B05 Key Words: Elliptic system; nonnegative entire solutions