The catalytic activity of benzaldehyde 1,2-propylene acetal was investigated from benzaldehyde and 1,2-propylene glycol in the presence of potassium dodecatungstocobaltate trihydrate (K ₅CoW ₁₂O ₄₀·3H ₂O). The effects of the cyclohexanone/1,2-propylene glycol molar ratio, the amount of the catalyst, cyclohexane dosage, the reaction time and the using regenerated catalyst on yield were studied systematically. The results show that potassium dodecatungstocobaltate trihydrate (K ₅CoW ₁₂O ₄₀·3H ₂O) is an excellent catalyst for the above reaction. The preferable experimental conditions are as follows: benzaldehyde/1,2-propylene glycol molar ratio is 1∶1.2, benzaldehyde is 0.1 mol, potassium dodecatungstocobaltate trihydrate (K ₅CoW ₁₂O ₄₀·3H ₂O) is 0.3 g, the volume of cyclohexane is 10 mL, and reaction time is 45 min. Under the above experimental conditions, the maximum yield of benzaldehyde 1,2-propylene acetal is up to 92.8%.