The seed rain and soil seed bank were investigated using seed traps, sieving and counting seeds in the soil, conducting seed germination experiments, and measuring seedling densities in the 18, 29, 40, and 54 years old Pinus tabulaeformis Carr. plantations and 75 years old natural Pinus tabulaeformis Carr. forest in Ziwuling mountain area in the Loess Plateau. The results showed that seed rain lasted from late of September to the end of November.The timing of the seed rain was positively correlaed with the plantation age. The process of seed rain falling is correlated with the forest age. The appearing time of seed rain is different with the rainfall peak time. Different Pinus tabulaeformis Carr. Plantations had different seed rain density. The density of seed rains in the different ages decreased in the following order, 40a plantation ((489.9±8.64) seeds·m-2) > 29a plantation ((346.8±7.45) seeds·m-2) > 54a plantation ((327.1±8.13) seeds·m-2) > natural forest ((146.9±5.25) seeds·m-2) > 18a plantation ((78.1±2.72) seeds·m-2). The seed rainfall peak is in 40a plantation and the seed rain activity is also the most active in it too. There was significant difference of seed bank in different plantations, with the 40a plantation is the maximum and the 18a is the minimum. From the start time of seed rain to next April, the total amount of siol seed bank was reduced by 42.34％ to 53.59％ in five different forest; Vacant seed had increased by 26.72％ to 48.69％; from April to august, the seed rot rate had increased from 1028％- 13.62％ to 57.25％- 63.28％. The main reasons for the seed bank lost were animal transportation, animal feeding and seed decay. The seed of Pinus tabulaeformis Carr was mainly located at litter lever and the soil depth of 0-2 cm and 2-10 cm were less than that of the litter lever. In the middle of August, 98.26% seeds of Pinus tabulaeformis Carr. was inactive. In different stands, the density of the seedling of Pinus tabulaeformis Carr. were significant different, followed as 40a plantation, 29a plantation, 54a plantation and natural plantation, The seedling was difficult to grow at 18a plantation. At a certain range of plantation age, the ability of plantation to seed setting and regenerated potentiality is improved with the plantation age increased. The regenerated potentiality of 40a is the highest. A great many of seed rain were occurred, but only a small amount of seed could exist which were caused by the seed lost and seedling death, besides, the effect of environmental sieve made the amount of mature individual was limited.