A spilt plot design field experiment with three replicates was conducted at Ibshway, Fayoum governorate, Egypt 2014/2015 winter season to study the interaction effect applying different organic manures (compost, chicken manure and farmyard manure) and three potassium levels (K₀, K₁, K₂ liquid potassium 38%) on ground spiders (Araneae) associated with tomato hybrid (010) in addition to tomato yield. Spiders were sampled using pitfall traps. Community composition of the organic, standard fertility of collected spiders was determined throughout the period of study using the Shannon-Wiener and Simpson Indices of diversity. A total of 63, 55, 113, 54 individuals included 14, 15, 13, 14 species in compost, chicken manure, farm yard manure and standard fertilization respectively. According to Simpson, it was found that farm yard manure included the highest number of dominant species. Most species caught belonged to family Lycosidae (92 individuals + one egg sac). Sørensen Quotient of Similarity between compost, chicken manure, farm yard manure compared with standard fertilization concluded that 79%, 89% and 74% of similarity. Statistical analysis proved that no significant differences were observed between means of both manures and potassium treatments while a significant difference occurred between farm yard manure K₁ and other manure treatments. The results of tomato yield revealed that there is a significant increase caused by chicken manure application and the highest increase in tomato yield was obtained with chicken manure (12.55 ton/fed), potassium had no significant effect. The interaction effect between organic manures and potassium levels on tomato yield had no significant differences although the highest yield was obtained by chicken manure with K₁ potassium level (12.71 ton/fed.).