P.G. Department of Chemistry, Sambalpur University, Jyoti Vihar, Burla Manuscript received 7 September 1974; accepted 13 January 1975 Uranium(IV) dimalate, U(C4H4O5)2, H2O has been prepared by photolytic method. The compound is green crystalline solid, sparingly soluble in water, insoluble in organic solvents but goes into solution when treated with alkali malate solution forming the complex ions, UM3-2 and U2M-2. Soluble complex compounds of the types, R2[UM3], nH2O and R2[U2M5], nH2O (where R =Na+, K+ and NH4+ and M = malate ion) are prepared by treating uranium(IV) malate in the aqueous solution of different concentrations of alkali malates. The i.r. spectra of the compounds are recorded and basing on the i.r. data the structures have been suggested.