  This paper summarizes the Multiple Parton Interactions studies in CMS,
focusing on the already performed low pT QCD measurements up to highest centre
of mass energies of 7 TeV and discussing the plans for the direct measurement
of the multiple high-pT scatterings. The underlying event in pp interactions is
studied measuring the charged multiplicity density and the charged energy
density in the transverse region, which is defined considering the azimuthal
distance of the reconstructed tracks with respect to the leading track-jet of
the event, defined from tracks according to a jet clustering algorithms. In
addition, we present the measurement of the underlying event using the
jet-area/median approach, demonstrating its sensitivity to different underlying
event scenarios. Observations in the central region are complemented by the
mea- surement of the energy flow in the forward direction for minimum bias and
central di-jet events. We compare our underlying event and forward results with
the predictions from different Monte Carlo event generators and tunes, aiming
to best parametrize the multiple parton interaction energy de- pendence
starting from the Monte Carlo tunes developed to best fit the charged particle
spectra measured at central rapidities. Finally we discuss the strategy to
directly measure the multiple particle interactions rate focusing on the
topologies with two hard scatterings in the same event.
