Pinus tabulaeformis forests as dominant communities in Ziwuling Mountain lying in Hilly Loess Regions, its nutrient distributions and bio-cycle patterns in both natural and artificial Pinus tabulaeformis forests were studied in this paper. The results were shown as follows: (1) Changes in nutrient contents for different components in the same Pinus tabulaeformis forest stood in the order of needles > branches > bark > roots > bole, and aboveground nutrient elements in needles, branches, bark, bole and litterfalls stood in the order of Ca>N>K>Mg> P (N contents were higher than other nutrient elements in needles, branches and bole for standⅠand in branches for stand Ⅳ), but nutrients stored in the soil stood in the order of Ca>K>Mg>N> P. The accumulative amounts of nutrient differed much among various forest stands because of differences in forest-ages. (2) The artificial forest with 30a had the highest nutrient amounts in Pinus tabulaeformis forest ecosystems, and accumulative nutrients in the arbor layer accounted for 0.76%～5.52% of total amounts, while that in the forest floor and litterfalls layers accounted for 0.05%～0.17% and 0.38%～3.48%, respectively. The accumulative amounts of nutrient increased first and then decreased with increased forest-ages in artificial Pinus tabulaeformis forest. The nutrient amounts reached maximum when the stand was 30-year, and decreased greatly when it was 50-year. Particularly, N contents decreased faster than other nutrient elements, and the reduction rate of N contents in the 30a Pinus tabulaeformis forest was 4.23 times as much as that in 50a stand. (3) The aboveground nutrients largely stored in the needles for Pinus tabulaeformis forest, and with increased forest-ages, needles not only increased its nutrient amounts, but also enhanced the proportion of total amounts in aboveground components. However, branches and bole only increased their absolute amounts, while decreased their proportions of total aboveground amounts. (4) The artificial Pinus tabulaeformis forest with 30a had the highest annual accumulative amounts of nutrient elements, and different stands stood in the order of Ⅱ>Ⅲ>Ⅳ>Ⅰ. Comparison of annual accumulative nutrient amounts in different components stood in the order of needles > branches > roots > bark > bole. Changes in annual amounts of various nutrients in the same component was similar to that in various components, that is, N>Ca> K> P>Mg in 10a young forests and Ca>N> K> P>M in artificial matured forests. So there is a parallel between natural forests and artificial matured forests. (5) The amounts of nutrient annually taken in from and annually retained in the natural forests were significantly higher than that in artificial Pinus tabulaeformis forest. With increased forest-ages, the amounts of nutrient annually taken in from and annually released to soil were increased in artificial Pinus tabulaeformis forest, but annually retained amounts increased first and then decreased. The nutrient use coefficient in various Pinus tabulaeformis stands stood in the order of Ca>Mg>N>K> P, but use efficiency of the same nutrient element decreased with increased forest-ages. There was no differences in use coefficient and turning over-period of nutrients in both natural and artificial matured Pinus tabulaeformis forest. The cycling coefficients of nutrient elements increased first and then decreased with increased forest-ages.