For organic chromium/HPAM weak gels，salinity（＜5000 mg/L）of NaHCO3 type oilfield wastewater has a huge impact on its gelation time and strength. The effect of salinity on the performance of organic chromium/HPAM weak gels，such as gelation time，gel strength，shear properties and viscoelastic were investigated by brookfield viscometer and RS150 rheology instrument. The experimental results showed that under the identical gelation condition，the gelation time shortened and the viscosity of weak gels raised as salinity increased. Salinity ranging from 2371.14 mg/L to 3084.60 mg/L had a significant delay effect on gelation， while the acceleration arose when salinity was beyond 3449.44 mg/L. Damage of shear on weak gel was not reversible. The weak gel with high salinity had higher viscosity at a low shear rate，while the viscosity with different salinity was similar at a high shear rate（≥21 s^-1）. Storage modulus G' and loss modulus G'' of the weak gels increased with the increase of salinity. Elastic of weak gel were dominant at high salinity，while viscous became dominant at low salinity.