Microstruture of squeeze cast 2024/20% SiC whisker composite was studied using transmission electron microscopy with energy dispersive spectrometry. Microstructure was oberserved at as-cast, solution treated. In as-cast condition, S`, θ`, S phase was observed in the matrix and at the interface Al_(15)(Fe, Mn)₃Si₂, θ, S phase was observed. After solution treatment, previous phase in the matrix were dissolved and Al_(20)Cu₂Mn₃ shape precipitate was observed in the matrix. Al_(15)(Fe, Mn)₃Si₂ phase which was formed in the casting stage was unchanged and Al_(20)Cu₂Mn₃ precipitate was observed at the interface.