Smilax glabra is climbing shrub. Tuberous roots are with obvious nodules and many fibrous roots. Stems are with no thorns. Leaves are alternate, leathery, lanceolate to elliptic-lanceolate, 6 to 20cm long, 1.2 to 5cm wide, and with acuminate apex, rounded base, and entire margin. Flowers are unisexual and dioecious; umbels are axillary and with very short peduncle; pedicel is slender and with many persistent triangle bracteoles; flowers are small, white, and about 4mm in diameter. Berry is red, spherical, and 6 to 8mm in diameter. Bloom time is from July to August and fruiting time is from September to October.