Changes of the soil organic carbon (SOC) and soil total nitrogen (STN) concentrations in paddy soil of Sichuan Basin were studied using the data of the Second China National Soil Survey and the data of soil samples collected in 2008. The results showed that the SOC concentrations in gley paddy soils were obviously higher than these in both the submerged paddy soils and the waterlogged paddy soils in 1982 and 2008. However, the STN concentrations in the three types of paddy soils showed different trends. The STN concentrations in gley paddy soils in 1982 were higher than these in submerged paddy soils and higher than these in the other two soils in 2008. The concentrations of STN and SOC increased sharply in the past 26 years and the increasing amplitudes of STN and SOM in the submerged paddy soils and gley paddy soils were higher than these in the waterlogged paddy soils. From 1982 to 2008, the SOC and STN concentrations in plain area, gully and toe of slope increased obviously and the increasing amplitudes followed the order: plain area > upper part of slope. The concentrations of SOM and STN were higher in the paddy soils generated from alluvium and mudstone due to the easier accumulation of SOC and STN in the soils. The easier accumulation of SOM and STN in weight loam soils led to the higher concentrations the SOC and STN in the soils compared with light loam soils. The increasing amplitudes of SOC and STN in the soils of winter paddy yield and rice-rape rotation were obviously higher than these in the soils of rice-wheat rotation.