To induce hybrid vigor by the reciprocal crossing with SWL (Sung Whan Line), MWL (Minnesota Line), AWL (Dembro Line) and BWL (Derby Line) of single comb white leghorn, 1,330 hens were divided into 16 blacks (Diallal cross with four Line) and fed under condition of N.R.C. feeding standard. In this experiment, hatchability, fertility, mortality, body weight, days required on up to first egg laying date, egg weight, egg quality, winter pauses, intensity, feed utilization, number of eggs layed during the testing period of days and brooding were investigated. Cross breeds showed a little higher fertility and hatchability but there were no significance when their parents had high hatchability. Cross breeds M♀×A♂, M♀×E♂ and A♀×S♂ showed more than ½ decrease in mortality, however cross bred hen showed 2.27% more decrease in mortality than purebreeds. Cross breeds of 6 blocks among 16 blocks at 6 weeks showed significant (P$lt;0.01) difference in body weight. Heaviest cross breed among all blocks were S♀×A♂ and A♀×S♂. Generally adult cross breeds showed heaviest body weight; especially in S♀×A♂ and A♀×S♂ cross breeds showed heaviest body weight among them. Dates requiring on up to first egg laying (50% laying date in the blocks) were showen at cross breeds. Cross breeds shorten 16.42 days than purebreeds and A♀×M♂ was showed shortest clay (171.0 days) in all cross breeds. ♀M×A♂ (175.0 days) and M♀×B♂ (175.0 days) were excellent. Cross breed showed increased egg weight as follows : A♀×S♂ 56.0 g, B♀×M♂ 56.62 g B♀×A♂ 57.40 g and there was significant (P$lt;0.05) difference in egg weight between pure breed and cross breed (M♀×S♂ and B♀×A♂), However, their egg weight was same one as standard (56.0 g) Generally productive block showed light egg weight, because egg weight are related to egg production, Those eggs didn`t show any progress in thickness, meat and blood spot. Winter pauses became more short and intensity was more higher than purebreeds. They produced more eggs during winter than purebreeds. Feed utilization was very high in cross breeds. than in purebreeds. The number of egg at 500 days testing period (Hen house) was M♀×B♂ : 201,08, S♀×B♂ : 200.73, B♀×S♂ : 200.21, M♀×S♂ : 197.28 and M♀×A♂ : 191.69 and number of egg per hen in the block was from 230 to 256 in a year. SWL and BWL cross was very excellent in any condition. Generally, we could say that the number of egg was increased by crossing and it showed at 1% level of significance, but cross breeds increased broodiness about 0.56% than did in pure breeds.