ABSTRAK KP PBB of Ngawi is government resort authorizes for Collecting Building and Land Tax (PBB) and also Income Tax of Right against Building and Land (BPHTB) as income resource of country. It is o ne of potential income resources of country, so that KP PBB tried to estimate the valuation (income planning) for the sake of efficiency and also affectivity in running monetary for development. The writer would like to compare a valuation made by KP PBB Ngawi based o n central government by using scientific method or forecast in determining exact method so that a valuation can be determined for maximal income. The method used is Least Square, Single Moving Average method, and also Kuadratic method. Forecasting Error Standart is the way used for determining whether its forecasting has been arranged by all methods has been reached. The result made based o n forecasting method concluded that valuation arranged by KP PBB Ngawi has been appropriate relatively than those arranged using Least Square method, Single Moving Average method, and Kuadratic method. It can be seen from the forecasting error standard estimation value. The value has smallest o ne than those used other scientific method 136,5. This proves that valuation estimation which is arranged has been close to the realization. Based o n the research, KP PBB is suggested to carry some corrections every years since the fact that certain targets sometime can be completed. It would be better if KP PBB find out economy-social and potency of Ngawi region in order to completethe targets.