H-FABPand A-FABPgenes are considered as candidates for intramuscular fat (IMF) accretion. The aim of the present study was to assess the expression of H-FABPand A-FABPgenes in m. longissimus dorsi(LD) and liver tissues of Laiwu and Lulai Black pig populations of different body weight (BW). Eighty-four barrows at different BW (30, 40, 50, 60, 70, 80, 90 and 100 kg, n= 6 per group) of Laiwu Black pig (no 100 kg group) and Lulai Black pig (no 30 kg group) were used to study the development changes of A-FABPand H-FABPmRNA expression and their relationships to IMF content. The results showed that, in both breeds, the IMF content increased continuously with growing (P< 0.05). The expression of H-FABPand A-FABPgenes also increased with growing in LD tissue (P< 0.05), and reached a peak at 50 and 70 kg BW in Laiwu and Lulai Black pig, respectively. However, this regularity was not observed in liver tissue in both breeds. A positive correlation was just found between the A-FABPmRNA expression level in LD tissue and IMF content and BW in both breeds (P< 0.05). In conclusion, the A-FABPgene is strongly related to the development and function of IMF accretion in pigs.H-FABPand A-FABPgenes are considered as candidates for intramuscular fat (IMF) accretion. The aim of the present study was to assess the expression of H-FABPand A-FABPgenes in m. longissimus dorsi(LD) and liver tissues of Laiwu and Lulai Black pig populations of different body weight (BW). Eighty-four barrows at different BW (30, 40, 50, 60, 70, 80, 90 and 100 kg, n= 6 per group) of Laiwu Black pig (no 100 kg group) and Lulai Black pig (no 30 kg group) were used to study the development changes of A-FABPand H-FABPmRNA expression and their relationships to IMF content. The results showed that, in both breeds, the IMF content increased continuously with growing (P< 0.05). The expression of H-FABPand A-FABPgenes also increased with growing in LD tissue (P< 0.05), and reached a peak at 50 and 70 kg BW in Laiwu and Lulai Black pig, respectively. However, this regularity was not observed in liver tissue in both breeds. A positive correlation was just found between the A-FABPmRNA expression level in LD tissue and IMF content and BW in both breeds (P< 0.05). In conclusion, the A-FABPgene is strongly related to the development and function of IMF accretion in pigs.