To investigate the effect of some bacterial and algal strains on induction of resistance against root-knot nematode (Meloidogyne javanica) in tomato (Solanum lycopersicum L.) roots.Application of Bacillus subtilis, Serratia marcescens, and Spirulina platensis on root area of nematode infected tomato plant, the number invading nematode, M. javanica, galls and egg masses in tomato roots were determined.The reduction percentage (94.97%) of developmental stages of root-knot nematode was highest in S. platensis treatment, among the biological agents and compared to 97.48 % in chemical pesticide Vydate treatment. The highest reduction percentage (90.43%) in female numbers was recorded with B. subtilis. All tested bioagents significantly increased vegetative weight of tomato plants. B. subtilis, S. marcescens and S. platensis increased the activity of peroxidase, polyphenol oxidase, superoxide dismutase and catalase in tomato plants infected with M. javanica.Biological control of nematodes using alga and bacteria that could potentially enhance plant health, productivity and promotes its growth.