  A quantum search algorithm based on the partial adiabatic
evolution\cite{Tulsi2009} is provided. We calculate its time complexity by
studying the Hamiltonian in a two-dimensional Hilbert space. It is found that
the algorithm improves the time complexity, which is $O(\sqrt{N/M})$, of the
local adiabatic search algorithm\cite{Roland2002}, to $O(\sqrt{N}/M)$.
