Hastelloy C-276 was subjected to 10% deformation and annealed at 1100°C for different times. The fractions of Σ3_n(n=1,2,3) boundaries and the connectivity of random boundary networks were characterized by electron back-scatter diffraction (EBSD). The results showed that the Σ3 boundary fraction is hardly increasing during annealing time. Instead, the fractions of Σ9 and Σ27 boundaries have a dramatic change with annealing times, whose peaks are arisen at annealed 15min. Meanwhile, the corresponding connectivity of random boundary network is effectively disrupted. This can be attributed to the incoherent Σ3 boundary producing more Σ9 and Σ27 boundaries and incorporating those boundaries into the random boundary networks. Actually, the connectivity of random boundary networks can be definitely identified by Σ(9+27)/Σ3 radio.