It is significant for coordinating regional economic development and carbon emissions' reduction to find the causes of spatio-temporal evolution of carbon emissions, the decoupling status of economic development and corresponding influencing factors. Thus, taking underdeveloped Jiangxi Province as an example, we analyzed the spatio-temporal evolution characteristics of carbon emissions, the decoupling status from economic development and corresponding influencing factors in the region, by using the IPCC carbon accounting method, Tapio decoupling model and Logarithmic Mean Divisia Index (LMDI), based on the industrial energy consumption data from 2002 to 2016. The results show that: (1) carbon emissions in Jiangxi Province increased rapidly in the early stage and slowed in the middle and late stages. Overall they increased from 6248.57×10⁴ t in 2002 to 18680.47×10⁴ t in 2016, with a growth rate of 198.96%. Carbon emission intensity showed a trend of rapid decline in the early and middle periods and slow decline in the later period, from 5.604 t per 10,000 yuan to 0.552 t per 10,000 yuan. The spatial distribution of carbon emissions and carbon emissions' intensity was generally high in the northwest and low in the southeast. (2) From 2002 to 2009 and from 2009 to 2016, decoupling was weak between economic growth and carbon emissions in Jiangxi, with the decoupling elasticity of 0.177 and 0.105, respectively. From 2002 to 2009, all cities presented a weak decoupling state; the decoupling elasticity in Ganzhou and Shangrao was relatively large, 0.504 and 0.440, respectively. The decoupling state of the southern and northern regions in Jiangxi was not ideal. From 2009 to 2016, the decoupling state in Pingxiang and Shangrao transformed to strong decoupling; their decoupling state was most ideal. The decoupling state transformed from weak decoupling to expansive negative decoupling in Fuzhou. Decoupling elasticity in Jingdezhen increased from 0.179 previously to 0.741. The decoupling state was poor in the northeastern region of Jiangxi except Shangrao. (3) From 2002 to 2009, the energy structure had a weak inhibiting effect on carbon emission decoupling in Jiangxi, which was, inversely, transformed into a tiny promoting effect from 2009 to 2016; the driving direction was different in different cities. Energy intensity played a leading role in carbon emission decoupling. The decoupling elasticity of the two stages was -0.329 and -0.481, respectively. Except for Fuzhou from 2009 to 2016, energy intensity played a major role in promoting carbon emission decoupling in cities. Economic level had a major inhibiting effect on carbon emission decoupling in Jiangxi; decoupling elasticity in the two stages was 0.377 and 0.475, respectively, which had a major inhibiting effect on carbon emission decoupling in various cities. Population level had a small inhibiting effect on carbon emission decoupling. Therefore, the focus of carbon emission reduction in Jiangxi is to improve energy structure and energy efficiency, promote the transformation and upgrading of traditional industries in Xinyu, Jiujiang, Pingxiang and other cities, and promote coordinated green development between the northwest and southeast regions of the province.