  The nonzero vacuum expectative values of sneutrinos induce spontaneously
R-parity and lepton number violation, and generate three tiny Majorana neutrino
masses through the seesaw mechanism in the $\mu\nu$SSM, which is one of
Supersymmetric extensions beyond Standard Model. Applying effective Lagrangian
method, we study the transition magnetic moment of Majorana neutrinos in the
model here. Under the constraints from neutrino oscillations, we consider the
two possibilities on the neutrino mass spectrum with normal or inverted
ordering.
