A research project undertaken during the period of 1960–1969 by the ‘‘Bussei Group’’ of Japan Synthetic Rubber Co. was reviewed, and the prologue and the epilogue for this long term project was presented. The overall framework was first shown as the target system of the project which aimed in correlating the quality of rubber products with the molecular characteristics of raw rubbers. Eight principal research areas were then identified to develop the subsystems which constitute the total system. For each of the research areas, a general way of approach to the rheological problems was shown and then some typical examples of the results thus obtained were illustrated. Finally, in the prologue, a review of the historical background of this research project was given, and in the epilogue, the reason by which this project had to come to an end was examined from a managerial point of view.