【Objective】 A laboratory incubation was conducted to study the transport characteristics of soil native carbon(C_s)and straw-derived carbon(C_str)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 C_s loss in the two soils were ranked as HF>OPOC>LF. Straw application increased the percentage of C_s loss in HF from 2.83% to 5.53%(P<0.05)in black soil and decreased the percentage of C_s loss in OPOC from 1.86% to 0.82%(P<0.01)in cinnamon soil. Importantly, the C_str 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 C_str in cinnamon soil showed no significant difference compared to that in black soil. The residual rate of C_str 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 ofC_str in LF of cinnamon soil.【Conclusion】The HF was the main source of C_s 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-C_str in cinnamon soil was lower than that in black soil and could be limited by nitrogen application.