The exploration for effective in-feed additives is growing owing to the global climatic change trend to alleviate the negative effects of heat stress in laying hens. This research assessed the potential of using B-glucan (G) as an anti-heat stress agent in Matrouh laying hens subjected to early heat shock programs during the growing period. Factorial design (3×3) was used, including three levels of heat stress (control, heat shock at three days and at three days and eight weeks of age) and three levels of β-glucan (0, 100 and 200 mg β-glucan /kg diet). During the first 12 weeks of egg production (EP), treatments were exposed to heat challenge. The results revealed that heat shock program applications at three days and eight weeks of age significantly decreased body weight at 36 weeks of age (P<0.05) and reduced (P<0.05) feed intake (FI). While significantly (P<0.05) improved feed conversion ratio (FCR), Hemoglubin, RBCs, WBCs, immunoglobulin M (IgM), immunoglobulin G (IgG), and Heat shock protein (HSP70) of the Liver (P<0.01) as compared with the control group. At the same time, there was a decrease in lymphocyte%, H/L ratio, cortisol, and T3 compared to the thermo-neutral control. When compared to the control group, hens fed a diet containing 200 mg of βG significantly (P<0.05) improved body weight at 16 weeks and final weight at 36 weeks, feed conversion (FCR) (g. feed/g. egg mass), hen-day egg production, and egg mass, as well as the digestibility coefficients of crude protein (CP), dry matter (DM), metabolizable energy (ME), and cortisol. The interactions between heat chock programs and βG levels were non-significant for the most studied traits except daily feed intake. Therefore, the early heat shock exposure two times and supplementation of Β-glucan (βG) at 200 mg/kg diet during the growth period for laying hens that are exposed to heat stress during the reproductive period could improve productive, reproductive performance, HSP70 level and enhance immunity responses.