This paper estimates the part of the quarterly regional GDP― private consumption, housing investment, private investment, and pubulic investment― in Kansai Economy for the purpose of promoting the utilization of regional economic data. The regional domestic expenditure index （RDEI） is used for estimation, comparing the Kansai’s share of the quarterly Japanese GDP as a benchmark. This study shows that Kansai’s share of private consumption has a declining trend, which affects the benchmark and estimated quarterly consumption. This study also shows that the difference between the estimated and the benchmark series is relatively small in case of housing investment, private investment and public investment.