Denduan Kingrungpet creator Igel, Barbara Chairperson Lee, Sang-kon Examination Committee Bechter, Clemens Examination Committee text series technical report th Bangkok Asian Institute of Technology 2001 continuing eng 72 leaves The differences of firms' resources and capabilities cause unequal of firm's competitive advantage in business competition. Management ability of its own resources and capabilities influences to core competence, which leads to competitive advantage as well. As a result of limited necessity determinants in competition, Thai small and medium food manufacturers, which must compete with MNCs and large domestic companies, are necessary to know and understand its own situation to adjust itself for competitive advantage in the future. In-depth interviews are conducted in eleven companies. The interviews' results show that new product capability of the firms can be divided into three groups. First, they use R&D to be main strategy. Second, they use R&D as competitive tool and the last group does not concern with product R&D. There are five factors that influence on new product capability of the firms. First, entrepreneur will determine direction of product development and provide resources for R&D researcher. Second, researcher capability drives progress and increases product criterion for the company. Third, economic situation will attract the firms in developing new product when it is good. Fourth, supplier gives an advice and provides material and equipment for R&D experiment. The last is government regulation. The firms have to plan perfectly before developing a new product as new product register must spend time on approve. From the in.terviews, core competence of small and medium food manufacturers in Thailand is not found. A research study submitted in partial fulfillment of the requirements for the degree of Master of Business Administration, School of Management Research Studies Project Report (M.B.A.) - Asian Institute of Technology, 2001 Small business Thailand Food industry and trade Thailand Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B07192 http://203.159.5.9/ait-thesis/detail.php?q=B07192 011213 20260818170001.0