  We find some constraints on the flavor changing vertices of the two Higgs
doublet model, from the \Delta M_{B_{d}} measurement. Although bounds from this
observable have already been considered, this paper takes into account the role
of a new operator not included previously, as well as the vertices \xi_{bb},
\xi_{tc} and \xi_{sb}. Using the Cheng-Sher parametrization, we found that for
a relatively light charged Higgs boson (200-300 GeV), we get that \lambda
_{tt}<1, while the parameter \lambda_{bb} could have values up to about 50. In
addition, we use bounds for \lambda_{tt} and \lambda_{bb} obtained from
B^{0}->X_{s}\gamma at next to leading order, and studied the case where the
only vanishing vertex factors are the ones involving quarks from the first
family. We obtained that \Delta M_{B_{d}} is not sensitive to the change of the
parameter \lambda_{sb}, while \lambda_{tc}<1
