  The correlation functions of one-dimensional Hubbard model in the presence of
external magnetic field was investigated through the conformal field technique.
The long distance behaviour of the correlation functions and their critical
exponents for the model in the presence of a magnetic field are established by
solving the dressed charge matrix equations and setting the number of
occupancies to one, as an alternative to the usual zero often used by authors
in literatures. Our result shows the critical exponents of the correlation
function grows monotonically with magnetic field and reduces to definite values
at zero magnetic field around various Fermi points.
