The special problems in this thesis aims to design and build a spray type water by chemical engine. Characteristics of the machine structure is made of angle steel 25 * 25 mm.(2. ") 80 cm long, wide 46 cm high. 110 cm and engine size etc. are 1.2 strength, speed, 7 horse000 rpm. The real work sprayer type water engine of the prototype. To find the performance and efficiency in real work by spraying herbicide in plantations, ขนาดพื้นที่ 6603 square meters, found that the prototype is effective in real work, is 1.02 Rai / hour.