One hundred and twenty samples of fresh Ras cheese collected from different localities at El- Behera Governorate were examined for the presence of formalin by Hehner's, flame and chromo tropic acid tests, then 10% of the positive samples (seven) were stored and tested during ripening period up to 90 days. Most of cheese samples (58.33%) contained formalin detected by flame and chromotropic acid tests, but 41.67% of the tested samples were positive by Hehner's method. The chromotropic acid test is accurate, rapid, simple, highly specific, sensitive, inexpensive, easy and quantitative method for detection of formalin especially during ripening period and with low concentrations in routine controls. These were great vanations in formalin content in different samples depend upon the chcese maker. Also, the quantities of formalin in tested samples of Ras cheese were not changed during ripening, whereas if revealed dangerous and highly toxic effect due to daily consumption of the cheese and at a long continuous intake of formalin it migh be harmful. It can be recommended that formalin must not be added to the milk used in manufacturing Ras cheese at any level.