The foraging territories of 2 subterranean termites, Coptotermes formosanus Shiraki and Reticulitermes flavipes (Kollar), were simulated using a model to explore how territorial intraspecific competition changes with 4 variables characterizing the formation of territory: the number of primary tunnels, N0; the branching probability, Pbranch; the number of territories, N; and the blocking probability, Pblock. The blocking probability Pblock quantitatively describes the probability that a tunnel will be terminated when another tunnel is encountered; higher Pblock values indicate more likely termination. Higher tunnel-tunnel encounters led to denser tunnel networks. We defined a territory as a convex polygon containing a tunnel pattern and explored the effects of competition among termite colonies on territory size distribution at steady state attained after sufficient simulation time. At the beginning of the simulation, N=10, 20,…, 100 initial territory seeds were randomly distributed within a square area. In our previous study, we introduced an interference coefficient γ to characterize territorial competition. Higher γ values imply higher limitations on network growth. We theoretically derived γ as a function of Pblock and N. In this study, we considered the constants in γ as functions of N0 and Pbranch so as to quantitatively examine the effect of tunnel structure on territorial competition. By applying statistical regression to the simulation data, we determined the generalized γ functions for both species. Under competitive conditions, territory size is most strongly affected by N0, while the outcome of territorial competition is most strongly affected by N, followed by Pblock and N0.