Abstract: Arccuthobium pini is a parasitic seed plant. This species causes damage to Pinus clensata in Xizang The branches of infection always swell and enlarge to the fusiform. The annual or biennial shoot of this species has a height of 5-10 cm,, and the old one up to 25 cm. It forms its flower buds in autunm or winter every year, and its flowering period occurs in early May to early June next year. The fruits mature in mid-September to early October. The seeds of this species can't only be locally dispersed by expelling from the fruits directly, but spread by birds in the distance.