Previous studies on mammals showed that peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) played a prominent role in regulating muscle fiber type transition and composition.  However, the role of PGC-1α in chicken muscle has seldom been explored.  To investigate the effect of PGC-1α on chicken skeletal muscles in this study, the PGC-1α gene was overexpressed or silenced in chicken primary myoblasts by using lentivirus, and then the effects of the PGC-1α gene overexpression and knockdown on the mRNA expression profile of genes related to myofiber type specificity were examined during fiber formation.  The results showed that overexpression of PGC-1α from proliferation to differentiation was accompanied by the up-regulated expression of Pax7, MyoD, and CnAα, which was significantly (P<0.01) increased after one day of transfection (1I).  The enhancement of MyoG, MEF2c, and MyHC SM expression lagged, which was improved significantly (P<0.01) after four days of transfection (1I3D).  Overexpression of PGC-1α decreased (P<0.01) the MyHC FWM expression after four days of transfection (1I3D), and it had no significant impact (P>0.05) on the expression of CnB1, NFATc3, and MyHC FRM during myofiber formation.  The effective silence (P<0.01) of PGC-1α by lentivirus mediating short hairpin RNA (shRNA) was detected after four days of transfection (1I3D) in cultures, and the lack of its function in chicken primary myoblasts significantly (P<0.01) down-regulated the expression of Pax7, MyoD, CnAα, MyoG, MEF2c, and MyHC SM, significantly (P<0.01) up-regulated the expression of MyHC FWM, and had no significant impact (P>0.05) on the expression of CnB1, NFATc3, and MyHC FRM.  These results indicated that the role of PGC-1α in regulating the fiber type specificity of chicken skeletal muscles might be similar to that in mammals, which interplayed with key genes related to myocyte differentiation and calcineurin signaling pathway.