This paper presents a systematic study of major and trace elements, and Sr Nd isotopes on leucogranites closely related to uranium mineralization in the Gaudeanmus area, Namibia. The results illustrate that uraniferous leucogranites are high in SiO2 (6881%~7602%, averagely 7311%) and K contents, with 096~107 of A/CNK (averaging 101), suggesting the sub alkaline metaluminous to weakly peraluminous rocks. The rock is enriched in light rare earth elements, with LREE/HREE = 253~771, (La/Yb)N = 214~1040, moderate Eu loss and high Rb/Sr ratios (203~550 with an average of 436); enriched in LILE, such as Rb, Th, U, K and Pb, and depleted in Ba, Nb, Ta and Sr. The initial 87Sr/86Sr ratios of the rock range from 073035~079345 with the εNd(t) values of -135~-174; the εNd(t) values of uraninites range from -148 to -165, and two stage Nd model ages cluster between 243~256Ga. Detailed elemental and Sr Nd isotopic geochemical characteristics infer that leucogranites were formed in the post orogenic extensional environment; the U rich pre Damara basement dominantly contributed to the ore forming material during the main mineralization epoch, whereas the additional uranium infilling at the hydrothermal superimposition reformation epoch possibly came from the primary uranium minerals themselves.