Influence of different dietary levels of both prelaying and layer Cat+ and stage of egg production (age) on the phosphatase profile (ALP and ACP) of shell gland in Japanese quails was investigated. Six hundred and thirty, three-week old female Japanese quails were reared upto sixth week of age on quail starter ration having three prelaying levels of dietary Cat+ (0.5, 0.7 and 0.9%). At the sixth week of age birds were subdivided into nine sub-groups and reared on quail layer ration with three dietary Ca'+levels (2.5, 3 and 3.5%) upto the 24~'' week of age. Thirty birds from each group/sub-group were sacrificed and shell glands were collected at the sixth,l6~' and 24°i week of age. The shell gland ALP and ACP were estimated and a positive correlation was noticed between the ACP and dietary Ca'+levels, whereas ALP was uninfluenced by dietary Cat+ and age. The activity of ACP was significantly higher in the highest Ca'+fed group at both sixth and 16~' weeks of age. Shell gland ACP might have an important role in the transfer of Cat± from blood ac: oss the shell gland mucosa to the egg shell