The present invention provides a spreading agent for agrochemicals having superior adhesion particularly for plant surface. The present invention also provides an agrochemical spray solution having a reduced risk of leaving the spreading agent for agrochemicals on a plant surface. The present invention relates to a spreading agent for agrochemicals comprising a carboxy-modified vinyl alcohol polymer (A) having a carboxy-containing monomer unit content of 0.1 mol % to 10 mol %, a viscosity-average degree of polymerization of 200 to 5,000, and a degree of saponification of 65 mol % to 99.9 mol %.