Two pot experiments were performed during the two continuous summer seasons of (2013&2014) at the wire proof greenhouse associated in Sakha Agricultural Research Station, Sakha, KafrEl-Sheikh governorate, Egypt. The experiment targeted to evaluate the effects with adding different rates of biochar(w/w) (C0=without biochar, C1=0.2%biochar and C2=0.4%biochar) with nitrogen fertilizer rates (N0=without nitrogen, N1=30 kgN.fed-1, N2=45 kgN.fed-1 and N3=60 kgN.fed-1) on guar plant (Cyamopsis tetragonoloba L.Taub) inoculated with Rhizobium isolate AZ2. Different attributes such as N-uptake, yield, yield components of guar and the residual impact on some biochemical properties associated with sandy soil were examined. The experiments were carried out in a complete randomized block design with three replicates. Results indicated that nitrogen, phosphorus and potassium contents of guar plants after sixty days from transplant significantly increased by typically the addition of 0.4%biochar+30 kgN.fed-1 (T11) in sandy soil compared to the control (without biochar+without nitrogen fertilization+without inoculation=T1). The identical trend was observed using N,P and k% in guar plant seeds at harvesting stage. Furthermore, amount of nodules, nodules dry weight, dry weight of plant after 60 days and seeds dry weight increased with (T11) compared with control (T1). In respect to high quality parameters of guar for instance protein% in seeds and leg-hemoglobin, T11 seemed to be the best treatment. Available nitrogen and phosphorus content of soil increased substantially with T13 (0.4%biochar+60 kgN.fed-1) compared with control, while available potassium increased along with T11. Also, catalase activity as a parameter regarding microbial activities gave typically the highest values with T11.