Abstract: To explore the formation of meat quality characteristics in different economical pigs（Sus scrofa）, the subcutaneous adipose tissue and longissimus dorsi muscle（LM） from 7-days-old and 180-days-old Landrace and Bamei pigs were taken and the paraffin sections were prepared. The size of subcutaneous and intramuscular adipocytes, and muscle fiber diameter were measured after HE staining. The expression levels of MyHC in LM were detected by real-time PCR. The results showed that the diameter and volume of subcutaneous adipocytes was significantly greater in Bamei pigs than in Landrace at the age of 7 days old, while there were no significant differences in the size of intramuscular adipocytes and intramuscular fat（IMF） content.The diameter and volume of adipocytes and IMF content were significantly larger in Bamei pigs than in Landrace at the age of 180 days old, while the muscle fiber diameter of Landrace piglets was significantly larger than that of Bamei piglets. At the age of 180 days old, there was a greater increment in Landrace than in Bamei pigs; the expressions of MyHC IIa and IIx in LM muscle of piglets were abundant, which were significantly decreased at the age of 180 days old, while the expression and proportion of MyHC IIb were significantly increased. However, MyHC IIx and IIa decreased and IIb increased more in Landrace than in Bamei pigs. These results suggested that the adipogenesis in late growth period was mainly the hypertrophy of adipocytes. From early birth to late growth period, the composition types of muscle fibers in Landrace and Bamei pigs changed greatly, and the transformation pattern of muscle fiber types was the same in these breeds, and the main difference was the change amount of transformation among muscle fibers.