The configuration of the left ventriculogram (LVG) was classified in 64 patients with hypertrophic cardiomyopathy (HCM) observed in ECG, and characteristics of the configuration and serial changes in SV1+RV5 and giant negative T (GNT) waves were studied. The LVG configuration was classified into the spade (15 patients), papillary-muscle hypertrophy (PMH; n = 23), oval (n = 24) and banana types (n = 2). The spade, PMH and oval types were observed for mean periods of 66, 90 and 91 months, respectively. Serial changes in ECG were as follows: GNT decreased from 16.7 ± 3.3 to 13.3 ± 5.1 mm in the spade type and decreased significantly from 16.9 ± 5.9 to 9.8 ± 6.9 mm in PMH but showed no changes in the oval type. SV<sub>1</sub>+RV<sub>5</sub> decreased significantly from 69.0 ± 14.9 to 58.2 ± 14.7 mm in PMH but showed no significant changes in the spade or oval types. Thus GNT decreased progressively in many patients with the exception of a few with the oval type. From these findings, we consider that apical hypertrophy had been established at the time of the initial LVG and changed over time thereafter in the spade and PMH types but that hypertrophy was still in progress in some patients with the oval type.