A new method for light nucleus reaction has been developed based on the uni
fied Hauser-Feshbach and exciton model. The: nuclear data calculation for n
+ C-12 reaction, as example, has been performed in order to-study the mech
anism and the characteristic. The comparisons of total outgoing neutron:and
alpha particle with the measured experimental data indicate that the way o
f calculation for light nucleus reaction are successful.