A pot experiment was conducted to test the effect of two selected seaweeds belonging to different taxonomic group's Chlorophyceae (Ulva lactuca) and Rhodophyceae (Jania rubens) as well as farmyard manure (FYM) on growth and biochemical parameters of Trigonella foenum-graecum (fenugreek). Physico- chemical analysis of FYM and biochemical characterization of the two selected algae including (elemental analysis, hormones and pigments) were measured. Also,   growth parameters of fenugreek  as shoot and root  length, total plant height, leaf area, fresh weight and biochemical parameters including  carbohydrates fractions (direct, total reducing value, polysaccharides), nitrogen fractions (in soluble protein, total soluble nitrogen  and total nitrogen), chlorophyll contents (Ch a , b ) and carotenoid in addition to fatty acids were estimated. The obtained results clarified that Jania rubens has a pronounced stimulatory effects on test plant if compared with Ulva lactuca and FYM respectively.  Since, the alga has a high amount of macro, micro elements as well as phytohormones indole acetic acid (IAA, 110 ug/g), Kinetin (Kin, 68ug/g), naphthalene acetic acid (NAA 50 ug/g) and gibberellins (GA3, 11 ug/g). The alga increased growth parameters (root length, 8.8cm, shoot length 9 cm, leaf area 1.6 cm and fresh weight was 0.40 g). The alga enhanced pigment fractions with special reference Ch (b) since it was 1.15 mg/g more than its irrespective values in Ulva and FYM. As well as insoluble protein was 19.09 mg/g, total soluble nitrogen was 39.71 mg/g and total nitrogen was 180 mg/g. Also, the alga has a promotive effect on total carbohydrates since it was 82.84 (mg/g). Moreover, the different treatments led to a reduction in saturated fatty acids (SFA) and increase the unsaturated fatty acids (USFA) if compared with control. The fatty acids profile was due to the reduction of C_18:0, C_20:0 and increase in C_18:1, C_18:2 and C_18:3.The objective of this study is to evaluate the effect of two selected marine algae Ulva lactuca (Chlorophyta) & Jania rubens (Rhodophyta) as well as FYM on some phenological and biochemical parameters of Trigonella foenum-graecum .