Abstract: MASS DISTRIBUT1ONS OF RESIDUES FORMED IN THE INTERACTION OF COPPER WITH 20－46MeV／U~(12)C IONSSUN TONGYU；LI WENXIN；WU DINGQING；LUO QINGZHENG；SUN RULIN；ZNAO LILI；YIN XINMIN；JIN GENMING（Institute of Modern Physics，Acdemia，sinica Lanzhou，730000）LIZE；JING KEXING；LI XINHUA（China Institute of Atomic Energy，Beijing，102413）Gross sections for 39 target residues from the interaction of copper with 20．5，24．0，27．5，31．1，34．8，42．3 and46．4MeV／u~(12)Cions have been determined by nuclear chemistry tech-niques. These data are used to obtain the charge distributions，the mass yield distributions and themean excitation energy.The experimental mass yield distributions are in good agreement with those calculated frommonte-carlo GEMINI.Key words~(12)C＋Cu r-Spectroscopy Mass yield distribution Sequential binary decay model