Powder metallurgy Ni-based superalloys are used extensively in hot section of advanced aeroγengines due to their excellent comprehensive properties. During creep,the deformation mechanism of Ni-based superalloy depends on the alloy chemistry,morphology and volume fraction of γ phase and service conditions. Generally, the microstructure of FGH95 Ni-based alloy is closely related to the heat treatment regimes and its creep mechanism and properties are mainly determined by alloy cooling at oil path or molten salt bath. The difference of creep mechanism of molten salt cooling alloy from oil cooling alloy is that the dislocation networks may be formed in the matrix and therefore decrease the steady strain rate during creep to prolong the creep lifetime of the alloy. Unfortunately, the formation mechanism of dislocation networks in FGH95 Ni-based superalloy during creep is still unclear up to now. For this reason, by means of creep property measurement, TEM observation and diffraction contrast analysis, the formation of dislocation networks in FGH95 Ni-based superalloy during creep has been investigated. The results show that the 1/2<110> dislocations are activated on the octahedral slip systems in the γ matrix of the alloy at initial stage of creep and then they continue to multiply through dislocation reaction. When the alloy enters into the steady stage of creep, two sets of slipping dislocations with different Burgers vectors would encounter on the same crystal plane to react and form a hexagonal dislocation network, or two sets of slipping dislocations on different planes would intersect to form a dislocation network with quadrangle cells. Generally speaking, the dislocation network formation can decrease the dislocation mobility and  therefore restrain dislocation cross-slipping to enhance the creep resistance of the alloy. In the later stage of creep, the dislocations pile up near the regions of γ/γ’ interface and cause stress concentration, so that the deformed dislocations in the matrix shear and enter γ’ phase through damaged dislocation networks in γ’/γ’ interface,which may be decomposed to form the partials and stacking fault.