This project discussed to the instrument of the relative moisture of the soil using the high frequency technique. The principle of this instrument is similar to the general RFID systems using the radio frequency of 900 MHz. The measurement of the soil moisture by sending the RF signal to the RFID tag which placed on the soil and receive the back scattered power to the receiver. This instrument can indicate a range of soil moisture at least 2 humidity range i.e. dry and wet soil. In addition, the instrument can also be displayed via the LCD.