The karst environment takes up 61.9% in area in Guizhou province, which leads to weak environment and backward economy. Contrastive studies on element content of rock, soil and agricultural production in carbonate rock area and non-carbonate rock area are made in order to find factors leading to low output and poor quality of agricultural products in karst area. The study shows that carbonate rock lacks nutrient elements with the trace element content in carbonate rock is only 3.532 27（×10-4）but the trace element content in clastic rock is up to 10.894 21（×10-3）. The effective element content in cultivated soil delivered from carbonate rock is low to 1.014×10-4 but up to 3.260 5×10-4 in cultivate soil delivered from clastic rock. The effective element content and total element content in cultivated soil delivered from clastic rock are 3 times higher than that from carbonate rock. High quality agriculture products such as rice, potato and tea mainly produced in non-carbonate area. And it is believed the low output and quality of products is resulted from the above-mentioned low trace element content and poor agriculture environment.