Abstract:There are two groups of methods, namely, the design based methods and the modelbased methods that are commonly used for the analys is of bottom trawl survey data based on swept area method. While the designbas ed methods enjoy wide application, the modelbased methods are seldom used in C hina. The Deltadistribution modelbased method is described and then applied for the estimation of small yellow croaker and silver pomfret in the Yellow Sea based on a survey conducted in autumn, 2000. It shows that the stock density of small yellow croaker was 66.3 kg·km-2and its 95% Confidence Interval (CI ) was (23.4,109.2) kg·km-2;the total biomass of small yellow croaker in the survey area was 14 626.9 t and its 95% CI was(5 168.4,24 085.5) t. Stock density of silver pomfret was 19.0 kg·km-2 and its 95% CI was(3.5,34.5 ) kg·km-2, the total biomass of silver pomfret in the survey area was 4 194.3 t and its 95% CI was(773.2, 7 615.4) t. The traditional designbased me thod, however, resulted in much wider confidence intervals with negative low lim its. The above results indicate that the Deltadistribution modelbased method may provide estimates with higher precision, and deserve a much wider applicati on in data analysis for the stock assessment using bottom trawl surveys.