This experiment was carried out to investigate. effects of methods obtaining anterior pituitary cells, number of the cells in culture medium, culture time and additional levels of GHRH on pGH secretion from the cells. Number of anterior pituitary cell obtained from 1g of tissue was 2.67×10^7 in shaking method(method I) and 1.14×10^7 in spinning method(method II). There was no significant difference in the number of anterior pituitary cell between two methods. Anterior pituitary cells were covered all over the petridish after 72hr in vitro culture and could lie used for co-colture with GHRII. Optimum number of anterior pituitary cell was 200×10³ when multi well plate with 1 ㎖ volume and 200㎟ bottom square was used for in vitro culture. Both in control and GHRH, concentration of pGH in the culture medium was gradually increased until 3hr after culture, thereafter the increasing rate was decreased until 4hr culture. GHRH showed significantly (p$lt;0.01) higher pGH concentration in culture medium from 1, 2, 3 and 4hr culture than control. Concentration of pGH in culture medium increased significantly (p$lt;0.01) when GHRH level in the culture medium increased from 0.1 nM to L00 nM.