Аннотация:From the results of photometric observations of some symbiotic stars, the (R-J), (J-K) and (K-L) colours of their cool components have been determined. It was found that the (R-J) colours correspond to later spectral types than the (J-K) colours. Classifying the cool components in accordance to their (J-K) colours in the IR range, the IR excesses should be observed in the L filter, as a rule.