Gas Turbines have a wide application in power plant and aerospace industries. Nowadays, based on welding of two different materials, some economic methods for repairing turbine blades have been developed. Creep is slow irreversible strain of materials at above 40% of their absolute melt temperature. Super alloys used for turbine blades operate at temperatures about 70% of their absolute melt temperatures. Therefore creep fracture and creep damage is very important in turbine blades. Creep is founded as a damage which must be considered to design of mechanical elements which will work in temperatures above their 40% of melt temperatures even in loadings below their yield strength. Creep leads to initiate crack in parts and cause degraded mechanical strength. In this dissertation, for assessing life of a repaired turbine blade, made of INCONEL718 and GH4049 super alloys, a method has presented based of FEM method. This is done by writing a sequence of macros in ANSYS APDL commercial software. Creep-time-stress-temperature and stress-rupture numerical data was required. After building a proper model, a transient analysis performed. Then, a stress rupture analisys after stress analysis of structure based on Larson miller parameter was performed. Having reviewed results, concluded that a combination of stress rupture and transient analysis is required and done. In transient analysis had seen that maximum stress is obviously a function of time and varies in location in alloy GH4049 base material. In all load cases, the criticalest element was in softer material and in position of 180 degree with respect of triangular circle. These results introduced us to perform a combination of transient and stress rupture analysis which results in shorter life than stress rupture life using time fraction damage rule by numerical integration over time. Results shows maximum stress occurs in GH4049 and in tiniest region aside filler metal. In all simulations, softer material had smaller life than other material. Life versus rotational shaft speed curves in semi log axis is provided for various temperatures. To see level of reliability, an experiment was designed and a same method used to predict life time of a two specimen set of pure lead and tin70%-lead30% and their creep behavior under a proper load was studied. FEM method had a good agreement with life assessment compared with experiment result and has only 6% difference with experiment result, in compare with 20% by Larson-miller method. From experimental analysis, it was concluded that damage fraction rule has better life prediction. Then It is concluded that for repaired metals, in case of creep simulation, using damage fraction rule has more precise answers to predicting life of them. Keywords: 1-creep 2-life assessment 3-repaired blade 4-transient analysis 5-larson miller 6-Monkam-Grant parameter 7-damage fraction summation rule