Abstract:【Abstract】 Objective To evaluate the positive predictive value in different size of thyroid nodules with different patterns of calcification by using ultrasonography.Methods 893 calcified nodules were included. Of the 893 nodules, 390 nodules were≤ 1 cm and 503 were>1 cm. The types of calcifications were defined as follows: several microcalcifications, one microcalcification, coarse calcification, crescentlike and eggshell calcification. They were divided into two groups based on the size. Positive predictive value was calculated. Results The malignancy risks of types calcification several microcalcifications, one microcalcification, coarse crescentlike and eggshell calcification in micro group were 825%, 737%, 511%, 462% and 333%, whereas they were 853%, 516%, 223%, 389% and 30% in macro group. The difference between one microcalcification and coarse calcification were statically significant.Conclusion Micronodules, especially with one microcalcification and coarse calcification patterns, were higher risk of malignancy than macronodules.