Copyright © 2010 Jinhuo Luo. This is an open access article distributed under the
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We study the permanence and extinction of a generalized Gause-type predator-prey system with periodic coefficients. We provide a sufficient and necessary condition to guarantee
the predator and prey species to be permanent and a sufficient condition for the existence of a
periodic solution. In addition we prove that when the predator population tends to extinction,
the prey population keeps oscillating above a positive population level.