Abstract: In winters,six different structures of gonadotrops (GTH cells) of meso- adenohypophysis in Clarias lazera can be found.GTH1 cells filled with secretory granules and with few granular endoplasmic reticulum (GER);GTH2 cells with some secretory granules;the GER with large cisternae;GTH3 cells with few secretory granules and with abundant large GER cisternae;GTH4 cells without secretory granules but with abundant vesicular GER;GTH5 cells are small and contain very small GER;GTH6 cells with a deformed nucleus.The various structure of GTH cells in winters makes difference in the breeding season.In this paper,the structure characterizations of TSH cells (thyrotrops) and STH cells (somatotrops) were described.The structure changes and its funtions in three secretory cells were also discussed.