>HI,all
> I copy the other people 's dll, and i add new this new exists project , then i set the breakpoint to this
>project but no interrput, how can i do to run the dll project ?

Do you mean that you want to debug the dll ?
For that you will either need the related *.pdb file or you will need to decompile (using, for example, Reflector: http://reflector.red-gate.com/download.aspx?TreatAsUpdate=1)