Residue tester for liquefied petroleum gas conforms to SY/T7509 test method for residue of liquefied petroleum gas. It is suitable for use to test the residue of liquefied petroleum gas. 1. The heater adopts stainless steel material. Heating rate is fast and the life time is long. 2. The heating output adopts solid-state relay, contactless, sparkless, noiseless, long life time, safe and reliable. 3. Digital display temperature controller, easy and flexible to operate. Temperature controlling precision is high. 4. The bath of the instrument adopts stainless steel material, corrosion resisting and oxidation resisting. It is suitable to all kinds of mediums 5. The instrument adopts compressor to do composite cooling. Cooling rate is fast cooling depth is big and have good stability. 6. The instrument got rational design, has attractive appearance and friendly to the environment.