The parameter characterizing and estimating for room temperature creep crack tip stress-strain field of commercially pure titanium TA2 were studied by testing, theoretical analysis and finite element (FE) simulation. Testing results indicate that for commercially pure titanium TA2, the primary creep will occur at room temperature. Theoretical analysis and FE simulation demonstrate that the stress-strain field at the crack tip under loading hold period is HRR field. Thus, the time dependent J-integral was proposed to characterize this HRR field, and an estimation method for the J-integral was provided. Then the FE simulation was used to obtain the time dependent J-integral of TA2 CT specimen under the condition of room temperature creep, which shows that J-integral may appropriately characterize the crack tip stress-stain field. At last, the J-integral obtained by FE simulation and the estimation method were compared, which proves the effectiveness and accuracy of the estimation method.