In this paper, the microporous structures in the samples of jujube trees with different growth rings were characterized by using synchrotron radiation small angle X-ray scattering (SAXS) method. The scattered images of different tree ring samples appear in a fan shape, indicating that there are needle-like micropores in jujube tree and the preferred orientation is along the lingo fiber axis. The long axis, short axis, long axis ratio, orientation angle and orientation degree of the micropores with the growth rings were calculated. The orientation angle and orientation degree are wavy with the whole ring. From the first ring to the second ring, the pores become thinner and longer, indicating that jujube trees grow rapidly. Subsequently, the growth rings and pores become shorter and thicker, indicating that jujube trees are flourishing and need to transport more nutrients through the pores of the trunk.