This study has done following (1)-(3).(1).Getting the data of investment to tax offices of Tokyo Metropolitan.(2).Analysis of work intervals for repair and reconstruction of these tax offices.(3).Analysis of characteristics of repair and reconstruction works.Main results of analysis are following (4)-(5).(4).Many of large scale repair works have done at 20-25 years after newly built them.(5).After large scale repair works, the ratio of equipments repair works in whole repair works grow larger.