The main objective of this research was to study farmer's knowledge to some outcomes of irrigation water users associations project in some villages of Damanhor & Abo-Homoss Destricts, Behera govemorate through identifying the difference between the knowledge levels of farmers whom applying the project for six years (qabil village in damanhor district) and whom applying the project for three years (besentway village in Abo-Homoss district) regarding: the operating type of the associations , the economic, social, technical outcomes , determining the difference between the knowledge levels of farmer's ,the sources of their knowledge levels and determining the major problems facing the farmers. The study was carried out in Behera govemorate,240 farmer's were selected randomly from 2 villages in two districts: qabil village in damanhor district the oldest district in applying the associations (since 1997) and besentwey village in abo-homoss district the recent district in applying the associations (since 2000). The data were collected by personal interviews using a pretested questionnaire. Data were analyzed statistically by using means standard deviation and t test, in addition to frequencies and percentages to present the results of the study. The main findings of the study could be summarized as follows: 78% of respondents have positive attitudes towards irrigation water users associations. There are significant differences (at 0.01) between the farmer's knowledge degree concerning operating the associations of economic, social, technical outcomes and the attitudes towards these associations .