This invention relates to a method of preparing cellulose solution which is homogeneous at relatively low temperature, in which a small amount of cellulose powder or polyvinylalcohol is dissolved in the liquid-state, concentrated N-methylmorpholine-N-oxide (hereinafter, referred to as `NMMO`) so as to lower the solidifying temperature of NMMO, and then, the resulting solution and cellulose powder are fed into an extruder so as to be mixed, swollen and melted in the extruder.