A new process for the direct chlorination of 2-chloro-5-methylpyridine to yield 2-chloro-5-chloromethylpyridine in an airlift loop reactor (ALR) has been studied. Five main reaction conditions including T-R, n(a)/n(s), c(p), Q(g) and d(D)/d(R) were optimized. The average molar yield and purity of 2-chloro-5-chloromethylpyridine obtained were 79% and 98.5% respectively under the optimum operating conditions. Finally, the efficiency for the preparation of 2-chloro-5-chloromethylpyridine with ALR and stirred tank reactor (STR) respectively was compared.