To understand response and adaptation of nitrogen (N) and phosphorus (P) stoichimetry to environmental changes, we conducted a provenance experiment on Larix gmelinii, the dominant boreal tree species in northeastern China. We collected seeds from six provenances with different geographical and climatic conditions and planted the seeds at a homogenous site in the southern boundary of the distribution range of this species for 32 years. Our objectives were to (1) examine variations in the concentrations of N and P in different organs among provenances, (2) explore monthly dynamics in the concentrations, and (3) explore correlations between N and P concentrations in different organs. The results showed that the N concentrations in the needles on old branch, fine roots (diameter 1-2 mm), and medium roots (diameter 2-5 mm) showed significantly different among the provenances (P < 0.05, P < 0.01, and P < 0.05, respectively), with the concentrations ranging from 21.1 to 24.2 mg/g, from 5.9 to 7.8 mg/g, and from 4.7 to 6.5 mg/g, respectively. The P concentrations in the needles on old branch and needles on new twig were significantly different (P < 0.05) among the provenances, with the concentrations ranging from 4.5-5.8 mg/g and from 4.5-6.5 mg/g, respectively. The N/P in the roots, branches and needles showed significantly different among the provenances (P < 0.05). The seasonal variations in the concentrations of N and P in the needles and roots trended to decrease first and then increase as the growing season proceeded, while those in the twigs showed a trend of increasing-decreasing-increasing. There were significant correlations between N and P concentrations in branches, needles, fine roots and medium roots. There were significant correlations between the N concentrations in the needles on twigs and on branches, twigs, branches and roots. The results suggest that the adaptation of Larix gmelinii trees to different environments in the six provenances lead to genetic differentiation in their stoichiometric traits of N and P.