The asymmetry term effects for the cross sections of (n, charged particle) and (n, 2n) reactions at 14-15 MeV neutron incident energy have been investigated. The effects of pairing and odd-even nucleon numbers in new data and in the formula of Tel et al. [J. Phys. G. 29, 2169[J. Phys. G. 29, (2003] are discussed. We have determined three different parameters groups by the classification of nuclei into even-even, even-odd, and odd-even (n, d) reactions. In addition, since there are not enough experimental data available, we have considered two different parameters groups by the classification of nuclei into odd-A and even-A (n, t) reaction cross sections. The empirical formulas with two parameters for the evaluation of the (n, d) and (n, t) reactions cross sections are discussed in the present study.