Integrins play an important role in muscle development. In developing chick skeletal muscle In Vitro, the integrin subunit alpha 1 has been shown to reorganize from a punctate to a periodic distribution along the AI junction subsequent to sarcomere assembly. Also subsequent to sarcomere assembly, laminin, a major component of the basement membrane, has been observed with a periodicity along the myofibril. Analysis In Vitro has shown that the periodic distribution of laminin and alpha 1 integrin are correlated both spatially and temporally and suggests a role for alpha 1 integrin in the establishment of the basement membrane. To confirm the distribution of these proteins in muscle development In Vivo, sectioned skeletal muscle from embryonic chick days 16‐20 was examined. Initially muscle sections were immunofluorescently labeled with antibodies to alpha 1 integrin and muscle specific proteins. Data indicated that alpha 1 integrin reorganized from a punctate to a periodic distribution beginning at day 16. By day 18 all myofibers examined were observed to have alpha 1 integrin periodically distributed along the sarcomeres. The temporal and spatial distribution of laminin in relation to alpha 1 integrin at embryonic days 16‐18 will be examined to determine the correlation of these two proteins in In Vivo muscle development.