  Standard model with intrinsic Lorentz and CPT violations is proposed in a
Finsler geometric framework. We present explicitly Lorentz and CPT--breaking
Lagrangians of the matter fields and the gauge fields in locally Minkowski
spacetime. The Lorentz invariance violation is found to be originated from the
spacetime background deviating from the Minkowski one. Similarly, the CPT
violation is determined by the behaviors of the locally Minkowski metric under
the parity and time reversal operations. To help understanding phenomenologies,
we compare the Finslerian model with the standard--model extension (SME) term
by term at a first order approximation.
