We study the attacking behavior of possible worms inWireless Sensor Network (WSNs). Using epidemic theory, we propose a susceptible-infectious-quarantine-recovered (SIQR)model to describe dynamics of worms propagation with quarantine in the wireless sensor network. Mathematical analysis shows that dynamics of the spread of worms are determined by the threshold R0. If R0 ≤ 1, the worm-free equilibrium is globally asymptotically stable, and if R0 > 1, the worm-endemic equilibrium is globally asymptotically stable. Lyapunov functional method as well as geometric approach are used for proving the global stability of equilibria. A numerical investigation is carried out to confirm the analytical results. As a result of parameter analysis, some effective strategies for eliminating worms are suggested.