【Objective】 A laboratory incubation was conducted to study the transport characteristics of soil native carbon (Cs) and straw-derived carbon (Cstr) after adding wheat straw and nitrogen fertilizer in black soil and cinnamon soil. 【Method】 There are four treatments: Control (soil only, no straw or nitrogen added), N (soil with nitrogen fertilization, 170 kg?hm-2), R (soil with straw addition, 8 580 kg?hm-2), RN (soil with nitrogen fertilizer 170 kg?hm-2 and straw addition 8 580 kg?hm-2). The wheat straw used was isotope 13C labeled. Soil samples were collected and fractionated into three different soil organic carbon fractions (light fraction-LF, occluded particulate organic carbon-OPOC, heavy fraction-HF) at 0, 180, 300 days. 【Result】 The results showed that the soil incubation was a carbon loss process of soil carbon mineralization. Nitrogen fertilization showed an inhibitory effect on carbon mineralization in both soils, and the effect in cinnamon soil was more significant in straw-added treatments compared to no straw-added treatments. The percentages of Cs loss in the two soils were ranked as HF>OPOC>LF. Straw application increased the percentage of Cs loss in HF from 2.83% to 5.53% (P<0.05) in black soil and decreased the percentage of Cs loss in OPOC from 1.86% to 0.82% (P<0.01) in cinnamon soil. Importantly, the Cstr in LF was gradually transferred to OPOC and HF, and the transfer became slower after 180 days. By the end of incubation (300 days), the total residual rate of Cstr in cinnamon soil showed no significant difference compared to that in black soil. The residual rate of Cstr in LF was 4.98%-8.52% in cinnamon soil and was significantly higher than that in black soil (1.71%-2.47%). Compared to R treatment, RN treatment almost doubled the residual rate of Cstr in LF of cinnamon soil. 【Conclusion】 The HF was the main source of Cs loss. Nitrogen fertilization inhibited carbon mineralization in the two soils. Straw addition exhibited a positive priming effect on the carbon mineralization of HF in black soil and an inhibitory effect on the mineralization of OPOC in cinnamon soil. The degradation degree of LF-Cstr in cinnamon soil was lower than that in black soil and could be limited by nitrogen application.