  Let $f=(f_1, f_2)$ be a regular sequence of affine curves in $\bC^2$. Under
some reduction conditions achieved by composing with some polynomial
automorphisms of $\bC^2$, we show that the intersection number of curves
$(f_i)$ in $\bC^2$ equals to the coefficient of the leading term $x^{n-1}$ in
$g_2$, where $n=\deg f_i$ $(i=1, 2)$ and $(g_1, g_2)$ is the unique solution of
the equation $y{\mathcal J}(f)=g_1f_1+g_2f_2$ with $\deg g_i\leq n-1$. So the
well-known Jacobian problem is reduced to solving the equation above.
Furthermore, by using the result above, we show that the Jacobian problem can
also be reduced to a special family of polynomial maps.
