Groundwater flow through karstic aquifer can be described as falling within a spectrum of conditions ranging from flow within very specific conduits (conduit flow) to widespread multiple fissures and small pores (diffuse flow). Previously developed methods for assessing where a particular karst flow type falls in this range have only been applicable at catchments scale, with no attempt to determine the predominant flow type at smaller scales. A new approach is introduced which estimates the type of flow in karst aquifers based on constant-rate pumping test analysis. The principal characteristics which may be used for discriminating between karst flow types are their heterogeneities and interconnectivities. In this study, a simple method is devised which gives the degree of heterogeneity of karst aquifers by re-evaluation of ordinary constant-rate pumping test data. The method yields a coefficient termed the ‘‘heterogeneity ratio’’ (HR), with units of percent, which reflects the variations in successive transmissivity values 'detected' by the outwardly-expanding cone of depression as the duration of the pumping test increases. Also for considering the effect of interconnectivity, the ‘‘flow dimension’’ is estimated using existing methods. A four-fold karstic aquifer classification scheme is proposed based on relationship between the two pumping test-derived parameters.