FIBROUS CELLULOSE， FIBROUS CELLULOSE-CONTAINING SUBSTANCE， MOLDED BODY， AND METHOD FOR PRODUCING FIBROUS CELLULOSE

The present invention addresses the problem of increasing the transparency of a composition obtained using ultrafine fibrous cellulose having a phosphorus acid group while suppressing yellowing of the ultrafine fibrous cellulose. The present invention relates to a fibrous cellulose which has a fiber width of 1000 nm or less and has phosphorus oxoacid groups or substituent groups derived from phosphorus oxoacid groups. If the amount of a first dissociating acid in the fibrous cellulose is denoted by A1 and the total amount of dissociating acids in the fibrous cellulose is denoted by A2， the value of A1 is 1.35 mmol/g or more and the value of A1/A2 is 0.51 or more. If a sheet is formed under prescribed conditions， the YI value of the sheet is 6.0 or less.