Reactions proceeding within chlorobenzene clusters were observed. Electron-impact-ionized dimer produced a variety of products according to the elimination of chlorine atoms and hydrogens. In 193nm laser photoionization, appreciable amount of H elimination product was observed even in unclustered case, which is very rare in halobenzene molecules. It has been proved that molecular elimination of $Cl_2$ contribute to the production of $(C_6H_n-C_6H_5)^{+}$, (n is 3 - 5). Intracluster reactions showed somewhat different products from the gas phase analogue. For evaluation of thermochemical data which are not available, we have determined the stable structure of $(C_6H_5Cl)_2$ and calculated its binding energy, 2.2582 kcal/mol, with PM3 semiempirical calculation. Further works on ionic species are remained for the future.