The voltanunetric behavior of a ketoglutarate (a-KG) at the hanging inercury drop electrode (HMDE) has beeninvestigated in acetate buffer solution. Under the optinmln experimental conditions (pH 4.5, 0.2 M NaAc HAc buffersolution), a sensitive reductive wave of a KG was obtained by lineal scan voltalimletpy (LSV) and the peak potentialwas 1.18V (vs. SCE), which was an ineversible adsolLotion wave. Tile kinetic parameters of the electrode processwere a 0.3 and k=0.721/s. There was a linear relationship between peak current ip, a:o and a KG concentration inthe range of 2x10-6-8x10-4 M a-KG. Tile detection limit was 8x10-7 Mand the relative standard deviation was2.0% (Cαkg=8x10-4M, n=10). Applications of the reductive wave of a KG for practical analysis were addressedas follows: (1) It can be used for the quantitative analysis of a KG in biological samples and the results agree well withthose obtained fronl the established ultraviolet spectrophotolnetric nlethod. (2) Utilizing the colnplexing effectbetween a KG and aluminum, a linear relationship holds between the decrease of peak current of a KG Aip and theadded AI concentration CAm in the range of 5.0 x10-6-2.5x10-4M. Tile detection limit was 2.2x10-6M and therelative standard deviation was 3.1% (CAm=4x10-5 M,n=10). It was successfully applied to the detection ofaluminum in water and synthetic biological samples with satisfactory results, which were consistent with those of ICPAES. (3) It was also applied to study the effect of AIm on the glutamate dehydrogenase (GDH) activity in thecatalytically reaction of a KG+NH+NADH=L giutalnate+NAD++H20 by differential pulse polarogTaphy(DPP) technique. By inoditolring DPP reductive currents of NAD+ and a KG, an elenlentary important result wasfound that AI could greatly affect the activity of GDH. Tiffs study could be attributed to intrinsic understanding of thealuminum's toxicity in etlzylne reaction processes.