In this paper the distribution properties of NO3-, NO2-, NH4+ and PO43- in estuary of the Huanghe River (Yellow River) and its near waters, their removal processes in estuary and their relations with phytoplankton during April to November 1984 were discussed. High concentrations of inorganic N (particularly NO3-) are found in the estuarine water and low concentrations in the offcoast water and in the northwest region of Huanghe River estuary, indicating clearly that the high concenration of NO3- is from Huanghe River water. The distribution of PO43- in the estuary region of Huanghe River is consistent with NO3-, etc., but average concentration of PO43- is higher in the: water of northwest region of Huanghe River estuary where the exchange of PO43- is better between sediments and water. The distribution of the atomic ratio between total inorganic N and PO4-P is similar to NO2- and their changes of time and space is very large. The data show that the rich inorganic N and PO43- in the estuary region of Huanghe River are not the limiting factor for phytoplankton growth and it is possible that low concentration of NO3- in the northwest region of Huanghe River estuary sometimes limits the growth of phytoplankton. The distributions of three forms of inorganic N indicate that NO3- in the water of estuary region of Huanghe River and NH4+ in the water of northwest region of Huanghe River estuary are main forms of inorganic N respectively. The relationships of inorganic N and PO43- to salinity indicate that the removal processes of various inorganic N and PO43- in estuary vary in different time. The negative linear relative relationship of NO3- to S indicates that the concentration of NO3- is controlled by its dilution in seawater in the range of S surveyed. At the same time, the biological removal is evident for NO3- because a large quantity of phytoplankton is found there. In addition to the above two factors, other way for the removal of PO43- is possible because of the buffering action of suspensions and sediments of estuary. Therefore, the conservation of PO43- is worse than NO3-.