Taiwan has a wealth of experience in employing a graded, or split-rate, property tax. It is believed that a graded property tax can increase the capital intensity of improvements to land, and thus improve economic activities. In order to achieve this, land value needs to be extracted from the price of an improved property. Despite the long history of a graded property tax in Taiwan, the accuracy and corresponding equity issues of land valuation have so far received scant attention. This study adopts a linear regression model with data sets of both vacant land and improved property to separate land and structure values. This approach solves the common problem of scarce land sales and the empirical results turn out satisfactorily. The empirical findings suggest that the ratio of land value to total property price varies across property types and age of property. In addition, the current practice is likely to contribute to assessment inequity, and consequently tax inequity. All these observations call for the need to overhaul the present property assessment system.