This study develops a modified method of TRIZ to improve safety in chemical process design. This method is modified by the theory of TRIZ, which is inventive problem solving theory, for retrofit design of chemical process considering safety. The original TRIZ is difficult to access to chemical process safety due to inapplicability and ambiguity of terminology in classification of these parameters. It is necessary to be modified TRIZ for chemical process safety. This study reorganized thirty-nine parameters of the TRIZ into six categories such as mechanic, operator, process upset, design, natural hazard and material. The modified TRIZ is tested to jacketed reactor and polyethylene reactor. (C) 2009 Elsevier Ltd. All rights reserved.