A total of 400 quarter milk samples were collected from 100 dairy animals breaded in three dairy farms in Suez Canal area examined by California Mastitis Test (CMT)and found that 102 samples were positive for subclinical mastitis(SCM). Positive samples microbiologically revealed thatthe most common bacterial isolates from subclinical mastitis cases were Staphylococcus aureus 92(90.20%), Staphylococcu sepidermidis18 (17.65%), streptococcus spp.79(77.45) and E.coli 35(34.31%). On the other hand, total yeast and mould count were 74(72.54). Chemical and enzymatic examinations inpositive CMT milk samples revealed that mean level of milk lactose %was 3.16±0.79, while the mean level of milk chloride %was 0.13±0.04 significantly higherin positive CMT milk samples, mean value of LDH andALP enzyme was503.52±14.21IU/ML and 723.77±21.30 IU/ML which significantly higher in positive CMT samples than negative CMT samples. Therefore, our study concluded that milk lactose, chloride and enzymes are consideredto be suitable diagnostic methods for diagnosis of SCM in dairy animals.