In order to investigate the effect of irrigation cut tension and applying of compost fertilizer on yield and yield components of Cowpea, the present split-plot factorial experiment based on randomized complete blocks design was conducted in research station of agricultural faculty, Islamic Azad University-Damghan Branch, during 2012-13 cropping year. The irrigation cut tension treatment (no tension, irrigation cut at the flowering and podding stages) as the main factor and two cultivars (Bastami and Damghani) and compost fertilizer (no fertilizer consumption and 10 tons fertilizer consumption) as the subplot factor were considered. The result showed that there was no significant difference between different cultivars of Cowpea in respect of all studied traits. The results also showed that Cowpea is sensitive to irrigation cut tension. All studied traits with the irrigation cut during the flowering and podding stages showed a significant decrease compared to the control treatment. Average grain yield (45 percentage), number of pods per secondary branch (33 percentage) and main branch (26 percentage), number of secondary branches (25 percentage) and the number of seeds per pod in the main branch (25 percentage) had the highest decrease compared to irrigation cut tension .The results also showed that Cowpea have shown a positive reaction to use of compost fertilizer. Also, the results revealed that Cowpea showed a positive reaction to the using of compost fertilizer. The results also indicated that the adverse effect of water shortage on yield and yield components of Cowpea can be reduced by using compost fertilizer. Results of correlation coefficients showed that seed yield of Cowpea had the highest significant and positive correlation with traits the number of seed per pod in the pod main branch (0.91**) and the number of pods per main branch (0.90**).On the other hand, the results of the analysis of correlation coefficients (path analysis) showed that the number of secondary branches traits, the number of seeds per pod in the main branch and plant height were the most effective traits in improving seed yield.