Abstract: The gamma counts detected corresponding to an incident energy consist oftwo parts in general. One comes from the region of resonant reaction. It is pro-portional to the nucleus of the target in the resonant region. The other comesfrom the nuclei met by the incident particles in its path except for those nucleusof the resonant reaction region. It is related to the non-resonant cross section andthe target thickness. The non-resonant counts, sometimes, account for a largeproportion of total gamma counts. But It has been taken no account in the references published up to now.