Protein　folding　study　is　one　of　the　main　ways　to　investigate　structural　stability　and　mechanism　of　proteins.　pi-pi　Interaction　has　been　focused　much　attention　on　its　role　in　the　stability　of　protein　structure　and　functions.　In　this　paper,　two　typical　protein　folds　of　alpha/beta　protein　were　selected　for　the　research,　pi-pi　interactions　of　205　low　similarity　protein　samples　were　statistically　analyzed.　The　results　showed　that　the　distribution　density　of　pi-pi　interactions　in　(alpha/beta)(8)-barrel　fold　was　higher　than　those　of　classical　Rossmann　fold　and　the　difference　was　more　significant　in　the　critical　local　area,　aromatic　amino　acids　easily　form　pi-pi　interactions　in　(alpha/beta)(8)-barrel,　the　three　7r-Ir　interaction　combinations　corresponding　to　Trp　appearing　in　(alpha/beta)(8)-barrel　were　significantly　higher　than　classic　Rossmann　and　(alpha/beta)(8)-barrel　fold　had　greater　ability　to　form　complex　7r-network　than　classical　Rossmann　fold.　In　a　word,　pi-pi　interactions　in　different　folding　types　of　alpha/beta　protein　exist　specificity.　pi-pi　Interaction　effects　the　stability　of　(alpha/beta)(8)-barrel　stronger　than　the　classical　Rossmann.