The present invention provides a spreading agent for agrochemicals having excellent spreadability particularly against surfaces of plant leaves. The present invention also provides an agrochemical spray solution comprising the spreading agent for agrochemicals, and that shows excellent storage stability (particularly viscosity stability) even during long storage. The present invention relates to a spreading agent for agrochemicals that comprises an ethylene-modified vinyl alcohol polymer (A) having an ethylene unit content of 1.0 mol % to 19 mol %, a 1,2-glycol linkage unit content of 1.2 mol % to 2.0 mol %, a viscosity-average degree of polymerization of 200 to 5,000, and a degree of saponification of 80 mol % to 99.9 mol %.