Near-threshold fatigue crack growth characteristics was investigated on the Ni-Cr-Mo-V low alloy steel, which has the different microstructure obtained by tempering at various temperature. The specimens were austenized at $950^{circ}C$ and then followed by tempering at $200^{circ}C$, $530^{circ}C$ and $600^{circ}C$. Strain rate was obtained from strain gauge attached on the crack tip and crack opening point was observed through load-strain curve. Threshold stress intensity range(${Delta}K_{th}$) was increased with increasing tempering tempuerature, but the effective threshold stress intensity rage (${Delta}K_{eff,;th}$) was not affected with the increasing temperature. Grain size increased with increasing tempering temperature.