In order to clarify the effects of sodium alginate and seaweeds extracted by complex enzymatic hydrolysis and alkaline hydrolysis on the growth，physiological indices and nutrient uptake of pear seedlings，a pot experiment was conducted.The results indicated that application of seaweed extract increased the leaf area，fresh weight of louver，root volume and net photosynthetic rate of pear seedlings.Compared with control，the leaf area was increased significantly by 27.76% and was the highest in the treatment of seaweed extracted by enzymatic hydrolysis at high concentration.Seaweed extracted by alkaline hydrolysis improved leaf area obviously，while there was no significant difference between seaweed fertilizer treatments.Compared to control，seaweed extract improved the malondialdehyde，the phosphorus and potassium content of leaves，and significantly reduced the proline content.Among them，the content of phosphorus and potassium of leaves were significantly increased by 30.17% and 7.00%，respectively，in the treatment of seaweed extracted by enzymatic hydrolysis at low and medium concentration.The principal component analysis showed that the treatment of seaweed extracted by enzymatic hydrolysis at low concentration was the highest in comprehensive score(1.21)，and followed by the treatment of seaweed extracted by alkaline hydrolysis at low concentration level(0.81).Comprehensive analysis showed that watering seaweed extract could improve the growth，promote phosphorus and potassium absorption of pear seedlings，among which the application of seaweed extracted by enzymatic hydrolysis at low concentration of 5 mg/L had the best effect.