Size content variations of the sized yarns treated with various size recipes and physical properties there studied. The results were follows: 1. There is a tendency for size content of the sized yarns to change by the varieties of adhesives mixing ratio. The higher acrylic copolymer size ratio the more increase of size content appeared. 2. The lubricants mixed to the size liquor affected the take up percentage of size. The higher the concentration of the lubricant the more decrease of size content appeared 3. Strength and elongation of the sized yarn are affected by sizing. When size content of the sired yarn are increased, strength is increased a little but variation of elongation is increased. 4. The antistatic effects of the sized yarns are improved by the mixing of lubricant or antistatic agent. Concentration of lubricant in less than 1.0%, antistatic agent in less than 0.4% are effectual to improve the antistatic effect. (Received Feb. 21, 1973)