This paper was aim to optimize the purification technology of Rehmanniae Radix Praeparata extract with macroporous adsorption resin. With the content of manninotriose as index, the absorptive flow and time were investigated, as well as kinds, amount, flow of eluent. D-101 type macroporous adsorption resin was the best choice for the purification of manninotriose. The optimized parameters were as follows: the content of manninotriose at 161.16-53.72 mg x g(-1), absorption time 240 min, eluting solvent of purified water, volume flow at 1.5 BV x h(-1), and eluant volume at 6 BV. D-101 type macroporous adsorption resin could significantly increase the purity of Rehmanniae Radix Praeparata extract with the advantage of high absorption, remove most part of impurity, and the effect of semi-works production was better.