In order to explicate the current state of natural Armeniaca sibirica population and predict the population dynamics in the future, were investigated three populations along altitude gradients in mountain areas of northern Hebei Province. According to the diameter at breast height (DBH) class of the tree, the age class structures of three A. sibirica populations were analyzed, static life tables were constructed by smoothing out technique, and comparative fluctuations cycles of the populations were carried out by spectral analysis. In addition, more analysis were performed to reveal the effects of altitude factors on population dynamics of natural A. sibirica and the mechanism of population renewal and maintenance. Furthermore, we provide the scientific basis for the protection and management of A. sibirica populations. The results showed as follows: (1) DBH decreased gradually with the increasing altitude. There were 15 age classes with the maximum DBH of 12.47 cm in the lowaltitude habitat of 872 m (H1), 17 age classes with the maximum DBH of 14.10 cm in the middlealtitude habitat of 1 131 m(H2), and 11 age classes with the maximum DBH of 8.76 cm in the highaltitude habitat of 1 328 m (H3). The individuals of each population showed H1(2 158) > H2(1 262) > H3(133). (2) The population structure dynamics of A. sibirica at different altitudes all belonged to the increasing type. V′_pi of each population was greater than 0, with the dynamic change of H2(57.51%, 3.38%)＞H1(47.42%,3.16%)＞H3(27.57%, 2.51%). (3) Life expectancies of A. sibirica populations were fluctuant for the same age class in different altitudes and for different age classes in the same altitude. In the three altitudes, the survival curves of the populations trended toward DeeveyⅡ type, and the mortality rate of each diameter stage had little change and tended to be stable. (4) The mortality rate of A. sibirica population showed 7 (H1), 6 (H2) and 3 (H3) peaks along altitude gradients, indicating that the number of death fluctuations in the life cycle of the A. sibirica population decreased gradually with the increase of altitude. (5) Population dynamic spectrum analysis showed that, there were obvious small periodic fluctuations in the population harmonics of A. sibirica as well as the effect of fundamental wave at different altitudes, the harmonics of A. sibirica population in H1, H2 and H3 altitude fluctuated at A2 and A8, A7, A5, respectively. The natural regeneration of its current populations is good. If not strong anthropogenic disturbances or severe natural disasters, A. sibirica would maintain the dominant position in the community．