To provide a modification process for silk yarn that can improve its functionality such as resistance to scratching or abrasion, to yellowing or browning, to washing and the like with a reduced amount of resin application without damage to fabric hand of the silk yarn.

The silk yarn is wound up around a perforated bobbin, as the yarn layers hold a large volume of spaces therein and dyed in a cheese- dyeing equipment, as the dyeing solution is circulated to carry out the scouring and the treatment with 0.1-5 normal aqueous solution of polyethylene glycol and the resin treatment. It is recommended that the treatment with the aqueous polyethylene glycol solution is followed by drainage and drying before the resin treatment.