We conducted a life span simulation for a LNG underground tank by reproducing actual construction process in a three dimensional multi-scale integrated analysis. Thermal stress at early age, control of cooling temperature after enclosing LNG, moisture transport and seismic action in long term operation etc. have been evaluated unitarily in order to predict continuous response behavior more precisely in time domain. Through this study, the validity of the conventional design method was verified. In addition, the multi-scale integrated analytical technique showed potential to be used practically not only for design verification but also for maintenance in the near future.