Legal analysis: If the real estate is rented, the rental income of the real estate is the tax basis of the real estate tax.

legal basis: article 3 of the provisional regulations of the people's Republic of China on real estate tax shall be calculated and paid according to the residual value after deducting 1% to 3% from the original value of the property. The specific reduction range shall be stipulated by the people's governments of provinces, autonomous regions and municipalities directly under the Central Government.

if there is no original value of the property as the basis, it shall be verified by the local tax authorities with reference to similar properties.

if the property is rented, the property tax shall be based on the rental income of the property.