Abstract: Lake Liang-tze is in the Eastern District of Hupeh Province and not far from the southern bank of the Liang-tze River.This highly productive lake has an area of 438.5 square kilometres;its long shore-line(470 km.)is highly diversified by numerous little bays of varied shape and size.A rather detailed limnological survey of the whole area was undertaken between March 1955 and February 1956.The physical,chemical,and biological characters of the water were investigated by two samplings each month:the detailed results are recorded and discussed in the present paper.