To obtain a starch paste not changing in color even by sunshine, having excellent stability, useful for a washing paste, by suspending a starch in water, adding an alkali to the suspension to gelatinize it and neutralizing the alkali with a specific neutralizer.

This starch paste is obtained by suspending a starch in water, gelatinizing the suspension by adding an alkali and neutralizing the alkali with a neutralizer which is a mineral acid such as hydrochloric acid, phosphoric acid, sulfuric acid, etc., except nitric acid or an organic acid alone or an acid obtained by mixing one or more of them and has pH 7.2-11.5, preferably 7.5-9.5. Preferably the starch is mixed with 0.1-0.5% (based on the total of the starch) of a surfactant as an antioxidant and further 0.05-1.5% of an antiseptic/ mildewproofing agent.