The fine atomic sources is the important factor in atom lithography,a experiment set-up for realization of ultra-high vacuum chromium atomic sources was reported.In our experiment system,the parameters are that vacuum more than 5.0×10-5Pa,temperature of chromium sources is 1650℃,the probable velocity of chromium atom is 960m /s,the numbers of chromium atoms out of oven is N=1.5×1017s-1.