In order to analyze effects of strain rate on consolidation characteristics of Busan clay, a series of constant rate of strain (CRS) consolidation tests with different strain rate and incremental loading tests (ILT) were performed. From experimental test results on Busan clay, it was found that the preconsolidation pressure was dependent on the corresponding strain rate occurring during consolidation process. Also, consolidation curves normalized with respect to preconsolidation pressure gave a unique stress-strain curve. Coefficient of consolidation and permeability estimated from CRS test had a tendency to converge to a certain value at normally consolidated range regardless of strain rate. An increase in excess pore pressure was observed after the end of loading without change of total stress on the incremental loading test, which phenomenon is called Mandel-Cryer effect. It was also found that rapid generation of excess pore pressure took place due to collapse of soil structure as effective stress approached to preconsolidation pressure.