Experimental and theoretical studies were carried out to analyse the flux decline behaviour of limed sugarcane juice and retention characteristics of its components (total dissolved solids, sucrose and colour) in a rectangular cross flow ultrafiltration cell. Retentions of sucrose and total dissolved solids were found to increase with increase in pressure and feed bulk concentration. A theoretical model was developed to describe flux decline, combining the effects of formation of a gel-like porous layer (constituting high molecular weight substances) and osmotic pressure controlled layer (constituting low molecular weight substances). Predictions were observed to be in good agreement.