%0 Journal Article %T A generalization of curve genus for ample vector bundles, I %A Hironobu Ishihara %J Mathematics %D 1997 %I arXiv %X A new genus $g=g(X,\ce)$ is defined for the pairs $(X,\ce)$ that consist of $n$-dimensional compact complex manifolds $X$ and ample vector bundles $\ce$ of rank $r$ less than $n$ on $X$. In case $r=n-1$, $g$ is equal to curve genus. Above pairs $(X,\ce)$ with $g$ less than two are classified. For spanned $\ce$ it is shown that $g$ is greater than or equal to the irregularity of $X$, and its equality condition is given. %U http://arxiv.org/abs/alg-geom/9709024v1