The local existence of solution of the initial boundary value problem for the following bad Boussinesq type equation utt-uxx-uxxtt-aux4+ux4tt=(u)xxu(0,t)=u(1,t)=uxx(0,t)=uxx(1,t)=0u(x,0)=φ(x),ut(x,0)=ψ(x)is studied,and the sufficient conditions of blow up of the solution are given.