A　graph　G　is　called　(H1,　H2)-free　if　G　contains　no　induced　subgraph　isomorphic　to　H(1　)or　H-2.　Let　P(k　)be　a　path　with　k　vertices　and　C-s,C-　t,C-　k　(s　＜=　t)　be　a　graph　consisting　of　two　intersecting　complete　graphs　K(s+k　)and　K(t+k　)with　exactly　k　common　vertices.　In　this　paper,　using　an　iterative　method,　we　prove　that　the　class　of　(P5,C-s,C-t,C-k)-free　graphs　with　clique　number　omega　has　a　polynomial　chi-binding　function　f(omega)　=　c(s,　t,　k)　omega(max{s,　k}).　In　particular,　we　give　two　improved　chromatic　bounds:　every　(P5,　butterfly)-free　graph　G　has　chi　(G)　＜=　3/2　omega　(G)(omega(G)-1);　every　(P-5,C-1,C-3)-free　graph　G　has　chi　(G)　＜=　9　omega(G).