Abstract: A new-type earth resistance automatic monitoring device which can be used in tank farm is introduced in the paper. This device is characterized by compaction, light weight, low price, high safety and reliability and easy to install. This device can uninterruptly monitor the earth resistance of tank farm on a 24-hour service basis. When the earth resistance of tank farm is beyond the set value, the alarm signal will be sent out to indicate the operators to take effective measures to deal with.