To give a high wet strength properties, temporary wet strength properties and dry strength properties and improved compression strength and compression resistance desired in rations applications of paper.

This paper contains aldehyde-modified cellulose having an aldehyde content of about 1 to 20 mmole per 100g of cellulose. Other modes include a method for producing cellulose aldehyde by a selective oxidation using a limited amount of an oxidizing agent, a limited amount of nitroxyl radical mediator and limited reaction conditions. The produced cellulose aldehyde gives an oxidized cellulose containing the aldehyde in an amount effective for suitably using for the production of paper having desired wet strength properties, temporary wet strength properties and dry strength properties including compression strength and compression resistance.