SPS(Space Physics Sensor) onboard the KOMPSAT-I, which was launched at 1999, had transmitted ionospheric plasma density and electron temperature during the solar maximum from June 2000 to August 2001, SPS IMS onboard KOMPSAT-I occasionally detected abrupt plasma density enhancement in low-latitude region, in which the plasma density abruptly increases in a narrow region. Statistical analysis of the data obtained during the entire operational period shows that the occurrence probability of these events has its peak value at the Atlantic region and at the Hawaiian region where the geomagnetic field strength is weak. And the occurrence frequency has no correlation with Dst index or F10.7 index. The correlation between plasma density and the electron temperature shows a wide variety, but the anti-correlated cases are dominant.