The 775 mohair samples were taken from the mid sides of Markhoz goats and analyzed for the evaluation of fleece traits. The variables were average fibre diameter (AFD), staple length (SL), true length (TL), percentage of continues medullated fibres (CMF), interrupted medullated fibres (IMF), kemp (K), clean yield (CY) and wax (W). Measurement of AFD, CMF, IMF and K were made with a projection microscope, from 300 fibres per sample. SL and TL of fleece samples were determined as average 10 randomly selected staple and 200 fibres per sample respectively. CY of the samples were determined by washing with SedoxNFK detergent and air drying to a constant weight at 20oC in the laboratory. Wax of the samples was determined by washing with Dicloromethan and air dried to constant weight. The environmental factors effects (herd, sex, age and colour) also were studied. Heritability were estimated with single trait analysis using restricted maximum likelihood (REML) with the animal model for AFD (n = 1234 records collected at 2000 - 2003) and YFW (n = 3213 records collected at 1990-2004) respectively. The effect of sex on SL, IMF and CY were significant (P<0.01), but had no effects on other traits. The female goats have longer SL (14.96±.21 vs 13.71±.40 cm), higher CY (82.16±1.07 vs 75.80±1.07 %) and lower IMF (0.20±0.06 vs 0.79±0.12 %) than the males. The effect of age on AFD, IMF, CY (P<0.01) and W (P<0.05) were significant. The least squares means of ADF, IMF, and CY increased from 27.92±0.65 micron, 0.24±0.09 % and 76.37±1.01 % at one year of age to 33.99±1.16 micron, 0.89±0.15 % and 80.99±1.37 % at six years of age, respectively. But least squares means of W decreased from 2.15±1.14 % at one year of age to 1.48±1.68 % at six years of age. The effect of herd on AFD, SL, CMF, CY, W (P<0.01), K and W (P<0.05) were significant. The ranges of AFD, SL, CMF, CY, K and W between herds were 6.69 cm, 1.92, 15.64, 2.37 and 0.5% respectively. Effect of colour on AFD, CMF, IMF (P<0.01)
