Aragonite calcium carbonate whiskers with a high aspect ratio were prepared by carbonization method using high concentration dolomite refined solution as the raw material. The calcium carbonate whisker samples were characterized by XRD， SEM， TEM， etc. The effects of carbonization temperature， stirring rate， CO₂ aeration rate， and aging time on the dispersion degree and aspect ratio of calcium carbonate whiskers were investigated. The results show that the optimum process conditions for the preparing calcium carbonate whiskers are as follows： carbonization temperature 80 ℃， CO₂ aeration rate 25 mL/min， stirring rate 200 r/min， and aging time 1 h. Under these conditions， calcium carbonate with a yield of 95%， whisker aspect ratio of 30~35， whisker content of 99.7%， whiteness of 99.9%， and uniform distribution can be obtained. The growth mechanism of calcium carbonate was analyzed. The results show that Mg²⁺ can inhibit the growth of calcite calcium carbonate and promote the growth of aragonite calcium carbonate during the carbonization process， and calcium carbonate whiskers have a preferential growth along （120） crystal plane.