This research aims mainly to identify the behavior of cotton farmers related to using of Trichogramma parasite in defeating bollworms ,including  their knowledge, attitude and implementation of the farmers respondents to the technical recommendations special to using of Trichogrammaparasite, in addition to determining the extension communication methods appropriate for providing those farmers with those recommendations, as well as determining the contribution of each variable of the independent variables studied correlated significantly in explanation the total variance incident in the degree of knowledge, the attitude and implementation of the farmers respondents this recommendations, finally to identify the constraints faced by farmers respondents when they use of this parasite.
 This research were conducted inBasion district in Gharbia governorate, where three villages were selected simple random sample from all the villages in this district,  the villages were: Ganag, Meet Shreef, and Mashall, respectively, from them it was selected systematic random sample amounted to 220 respondents representing 10% of the total cotton farmers, whom amounted to 2200 farmers, data were collected by using interview in November 2010 after initially tested and make necessary adjustments, frequencies, percentages, arithmetic mean, standard deviation, weighted average, Pearson's simple correlation coefficient and the model of multiple regressions of upward step-wise were used to analyze data statistically 
The main findings were as follows:  
1- 58% of the farmers respondents were medium knowledge with the technical recommendations special to the using of Trichogramma parasite in defeating bollworms, while 54% of them were neutral attitudes towards the use of this parasite, and 49% of the farmers respondents were low implementation with those recommendations.
2- The most important methods of extension communication appropriate to supply the farmers respondents with the technical recommendations special to special of Trichogramma parasite in defeating bollworms from there point of view are: the field visits,  the demonstration fields, the demonstration practice, the extension panels, and the T.V agricultural programs.
3- There were seven independent variables collectively, explained 49,1% of the total variance incident in the knowledge of the farmers respondents with the technical recommendations special to using of Trichogramma parasite in defeating bollworms, 34,7% of this variance is attributable to a variable of education degree of the respondent, 6,2%  due to the variable of leadership degree, 2,8% due to the variable of exposure to sources of information to the use of Trichogramma parasite in defeating bollworms, 1,8% due to the variable of extension communication, 1,2% due to the variable of willingness to change, 1,2% to the variable of number of years of use Trichogramma parasite in defeating  bollworms, and 1,2% of the variance due to the variable of the  participation in agricultural extension activities.
4- There were five independent variables collectively explained 43,8% of the  total variance incident in the farmers respondents attitudes towards the use of Trichogramma parasite in defeating bollworms, 31,2% of them attributed to the variable of education degree of the respondent, 6,3% due to the variable of exposure to sources of information special to the use of Trichogramma parasite in defeating bollworms, 3,4% due to the variable of knowledge about the benefits of the use of Trichogramma parasite in defeating bollworms, 1,8% due to the variable of leadership degree, and 1,1% due to the variable of satisfaction of the economic returns from the use of Trichogramma parasite in the fight against bollworms.
5- There were four independent variables collectively explained 40,2% of the total variance incident in the implementation of the farmers respondents to the technical recommendations special to using of Trichogramma parasite in the fight against bollworms, 32,3% of them attributed to the variable of education degree of the respondent, 4,6% due to the variable of number of years of use Trichogramma parasite in defeating bollworms, 2,1% due to the variable of satisfaction of the economic returns from the use of Trichogramma parasite in the fight against bollworms, and 1,2% due to the variable of size of the area cultivated with cotton.
6- The most important constraints faced by farmers respondents when using Trichogramma parasite in defeating bollworms, they were: lack of awareness of farmers respondents in how to use Trichogramma parasite, absence of areas cultivated with cotton collectives, scarcity of extension panels on the use of Trichogramma parasite, the lack of extension manuals on the use of Trichogramma parasite, failure in involving farmers in the process of fixing cards of parasite in the field, no commitment of the farmers with the dates of spraying chemical insecticide after launch parasite in the field, and the lack of outlets for the sale of Trichogramma parasite.