In oder to obtain basic design data of water supply systems in apartment houses, the authors have investigated water consumption in the Metropolitan apartment houses. In this report, the authers compare the investigation results in 1988 with the results of examination in 1974, and also describe hourly and daily change of water flow rate, peak flow rate, instantaneous flow rate, etc. The results are summarized as follows; 1) In the household water consumption, the peak flow rate is larger in the evening than in the morning. 2) Especially in the small scale apartment house, this survey has proved that the value suggested by Hunter's simultaneous water flow rate was unnecessarily large. 3) In the case of small scale apartment house, there is a possibility of the insufficient capacity in water supply system designed by commonly used peak rates. 4) Automatic measuring systems introduced here were an extremely useful method for the water consumption survey of individual pipe line and continuous measurement over the long period of time.