The history of hydrological services of People'e Republic of China may be described as three periods,i.e. the period of rapid development (year l949-1957),the period of undulant development (year l958-l978) andthe period of advance due to reform and open policy (year l979-l999). Great achievements have been gained inmany fields 0f hydrological services including hydrological data acquisitin and processing, hydrological informationoand forecasting, hydrological analysis and computation, water resources assessment, the relevant researches, educa-tion and international cooperation. All of above those have contributed a lot to the socialist construction. At pre-sent, the hydrological services are facing new challenges and opportunities, and must make big strides forward continuously in order to meet new urgent requirements.