| Soil environment protection and sustainable development of agriculture are very important issues of today's research work. With the rapid development of economy and industry-agriculture production, heavy metal contaminated soil aroused huge concern from every part of the whole society, which could be regarded as a serious social problem. Chongqing is one of the most famous areas affected by acid deposition. Soil in this region had been polluted by various heavy metals because of human activities, and acid rain made this problem deteriorate further. Until now, research on soil pollution and corresponding control measure still had defects owing to lack of comprehensive investigation to soil pollution. As for different agro ecologic zones, major contradictions of soil pollution were poorly understood, therefore, divisional remediation was hard to realize. Consequently, the corresponding countermeasures also lacked specific target.Based on those above reasons, aiming at pollution situation of soil in Chongqing area, and by means of spot check, literature search, and indoor simulation, we investigated concentration and distribution characteristic of lead and cadmium in agricultural land of Chongqing, discussed environmental capacity of these two heavy metals in Chongqing. Furthermore, we also analyzed acid rain's impact on transferring of cadmium and lead in soil, which could provide scientific basis for protection of agricultural environment in Chongqing, and control of agricultural non-point source pollution, as well as safeguard to agricultural product.Based on large scale sampling of soil-crop (paddy, corn) from typical land of Chongqing, 430 soil samples (yellow soil, purple soil) and the same quantity of crop samples were collected from 39 counties and districts of Chongqing. Cadmium and lead concentrations of these samples were measured, and leaching experiment by acid rain was also simulated at the same time.Results indicated that cadmium concentration in typical soils of Chongqing ranged from 0.040 to 4.740mgkg"', with geometric mean value of 0.357mgkg-1, which was 1.68 times higher compared to background concentration of cadmium in Chongqing (0.133mgkg-1), and it was 4.95 times higher than worldwide mean value(0.060mgkg-1). As for lead, its concentration ranged from 7.425 to 309.175mgkg-1, with geometric mean value of 51.989mgkg-1. The relationship between cadmium and lead concentration was significantly correlated, which indicated the two heavy metals might have a same source, variance coefficient of cadmium exceeded 100%, which was highly influenced by external pollution. While external accumulation of lead was quite prominent, but its variance coefficient was much lower than that of cadmium. Lead contamination in soil might be quite even and prevalent.The mean concentrations of cadmium and lead in corn of Chongqing were 0.060. 1.835mg kg-1respectively, while these two indexes in paddy were 0.088, 0.673mg kg-1. Mean concentration and variance coefficient of cadmium and lead in paddy were higher than those of corn, which indicated that heavy metal content in paddy might be more likely to be influenced by environment condition and human factors. Excessive heavy metal concentrations were detected in both crops. The overrun rate of cadmium and lead in paddy were 72.81% and 5.10% respectively, and the highest values were 2.20 and 2.31 times higher than the standard. For corn, the overrun rate of cadmium and lead were 65% and 38.1% respectively, with the peak values 5.61 and 3.90 times higher than the standard. Results showed cadmium concentration in soils was significantly correlated with cadmium content in corn or paddy, while the relationship between lead concentration in soils and that in corn or paddy appeared to be insignificant.According to X2-Test and histogram, distribution character of cadmium, lead concentration in typical agricultural land of Chongqing was logarithmic normal school. Cadmium concentrations were mainly from 0.315 to 0.525 mgkg-1, and lead concentrations were prima...
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