Two field experiments were carried out during 20030004 and 200412005 seasons to study the effect of phosphorus levels on growth attributes of some local wheat (Triticum durum) cultivars at Al—Gabal Al-Akhdar, Libya. A split plot design with three replication was used in both seasons. The main findings could be summarized as following: All studied characters were increased with increasing plant age. The difference between wheat cultivars among all studied traits except plant height at tillering stage in the first season were insignificant at all growth stages in both seasons. Zarda cultivar tended to give the highest value of all studied traits, except photosynthesis efficiency (PE) at tillering stage, at all growth stages in the first season. The superiority of Zarda cultivar was true for extension coefficient (-01) at seedling and tillering stages, PE at elongation stage, net assimilation rate (NAR) at seedling stage, leaf area index (LA!) and plant height at seedling stage, biomass duration rate (BDR) and crop growth rate (CGR) at all growth stages and specific leaf weight (SLW) at seedling and elongation stage in the second season. Margawi cultivar produced the lowest values of all studied characters at all growth stages in both seasons. The highest P levels (45kg Pfha.) gave the highest values of Ec at tillering stage, PE, LAI and LAR at seedling stage, BDR and CGR at seedling and tilling stages. Whereas, increasing P levels up to (35 kg Plha.) increased -ol, PE, LAl, LAR and BDR to the highest values at elongation stage. The differences between the highest two P levels were insignificant at all growth stages in both seasons. The interaction between cultivars and P levels had a significant effect on plant height and leaf area ratio (LAR) in the first season only.