The main purpose of this research was to study participation of agriculturist to reduce pesticide and analysis the factors that have an effect on Pomelo Orchard in Amphawa District, Samut Songkhram Province. The two hundreds and eighty-two questionnaires were tools to collect information from three sub-district as Bang Nang Li, Bang Khae and Suan Luang. The data was analysis using Mean and SD statistical. The focused groups of agriculturist was used to study the factors have an effect on using pesticide of pomelo orchard.

The results showed that the level of participation of agriculturist to reduce pesticide and weed control chemical in Amphawa District was average value as 2.89 that was medium level.  Level of participant plans and decision-making of orchardist was average value as 2.58. The orchardist participated in agriculture was average value as 2.77. The benefit and assessment       from participation of agriculturist were average values as 3.50 and 2.73, respectively.  The participation  factors affect to agricultural without pesticide and weed control chemical in  Amphawa District that found many parameters such as personal factors, economic and social factors, awareness of information, state mechanisms, people, development and motivation.