The field of views of the Syowa East HF radar covers over Zhongshan Station (magnetic latitude ~ 74.5°S). We examined the relation between HF radar signatures and optical aurora by using the data obtained on 3 August 1997. A geomagnetic negative sudden impulse (SI(-)) occurred at ~ 1432 UT on 3 August 1997 associated with the sudden decrease of solar wind plasma density. From the behavior of the optical aurora observed by all-sky TV camera and scanning photometers at Zhongshan Station, a sudden enhancement of auroral emission intensity and poleward moving signature occurred associated with the negative Sl. It is interesting that the temporal and spatial variations of the HF radar backscatter power showed one to one correlations with optical aurora data. The details of this event are examined and compared with the data onboard WIND satellite and from ground based magnetometers
