This study was conducted to determine the replacement effect of spray dried plasma protein (SDPP) withdried porcine solubles (DPS) in weaning pigs. An ileal digestibility trial, at first, was conducted to formulatethe experimental diets with SDPP or DPS. Six piglets (21-d old and 6.12kg BW) with T-cannula in theterminal ileum were used. In a feeding trial, 180 pigs (21-d old and 5.98kg BW) were alloted in a completelyrandomized block design. Treatments were T1 (SDPP 5%, DPS 0%), T2 (SDPP 5%, DPS 2.5%), T3 (SDPP2.5%, DPS 0%), and T4 (SDPP 2.5%, DPS 2.5%) for phase I, and T1 (SDPP 3%, DPS 0%), T2 (SDPP 3%,DPS 1.5%), T3 (SDPP 1.5%, DPS 0%), and T4 (SDPP 1.5%, DPS 1.5%) for phase Ⅱ. Phase Ⅰ(0～1 week)diet was formulated to contain 3,300ME kcal/kg and 1.25% digestible lysine, and phase Ⅱ (2～3 week) dietcontained 3,320ME kcal/kg and 1.10% digestible lysine. Chemical pompositions of the protein sources werehigher in SDPP than DPS: CP (81.60 vs. 56.01), lysine (5.95 vs. 3.36), and methionine (1.85 vs. 1.22).Apparent ileal digestibilities of arginine, isoleucine, leucine, lysine, methionine, threonine and phenylalaninewere higher in DPS than SDPP (p<0.05). The apparent ileal digestibility of essential amino acids (average)was also higher in DPS than SDPP (p<0.05). There were no significant differences (p>0.05) in ADG andADFI of piglets during phase Ⅰ (0～1 week) and Ⅱ (2～3 week) among treatments. However, during phaseⅡ, T2 showed better FCR than T1 (p<0.05). During the overall period, there was no significant differencein growth performance among treatments. When DPS was partially replaced for SDPP, the diet cost wassignificantly reduced (p<0.05) in terms of cost/kg of body weight. In summary, the digestibility of DPS wasexellent, and it would be concluded that DPS can be partially replaced in the young pigs' diet containingSDPP in order to reduce diet cost in weaning pigs.