Abstract: Comparative analyses have established correlations between the amount of certain trace metals in human organs and the frequency of cancer, and the role of metals in the function of many enzymes has been well documented. Therefore, attention is drawn to the general importance of the distribution of these elements in normal and tumour tissues. A number of metals are concerned in the causation of cancer while others are connected with the antitumour activities. From the evidence accumulated in the literature, it is shown that various elements, particularly the first row of the transition elements in the periodic chart, are capable of exerting either effects. We have therefore prepared the transition metal complexes related to ethylene- diaminetetraacetic acid and nitrilotriacetic acid whose antimonial chelates have been given clinical trial as antitumour agents. Either ⅠorⅡ, on treatment with metal acetate or metal chloride, gave the corresponding metal complexes by the mole ratio of 1 : 1. The corresponding metal complexes of Ⅲ were similarly prepared. In such complex salts one mole of chelating agent combined with two metal atoms. Preliminary pharmacological tests revealed that Ⅱ-As, Ⅲ-Cu, Ⅲ-Co produced a slight inhibition on the growth of sarcoma 180.