For the zooplankton, qualitative and quantitative analyses were simultaneously carried out. A No.2, GB36 mesh net was used for the qualitative investigation; moreover, a 2-L water-collecting bottle was used for quantitative counting. Physico-chemical factors are analyzed according to the “Provisional Regulations for Investigation of Marine Pollution”, which was issued by the State Oceanic Administration in 1979. Eleven factors were considered; therefore, there are 990 parameters in total (i. e. 30 parameter × 11 × 3 sampling stations). The number (ind/L) of the zooplankton as the generating sequence {X₀ (t)},and temperature (°C), salinity, dissolved oxygen (mg/L), pH, chlorophyll-a (μg/L), phosphate (μg/L), nitite (mg/L), nitraite (μg/L), Fe and Mn, as the sub-sequence{X_i (t)} (i = 1, 2. …, 10) were calculated. On the basis of grey incidence, the correlation degree between the reference sequence (zooplankton) and compared series (the seawater physical and chemical factors) were estimated. The results show that Mn, Fe, chlorophyll-a and dissolved oxygen were more important for the zooplankton of biomasses than other substances.