Lightweight DES Algorithm (DESL) was introduced by Axel Poschmann et.al as a strong, compact and efficient encryption algorithm suitable for constraint resource like WSNs, RFID and IOT devices. This paper discusses the security of the DESL against Linear Cryptanalysis which is a known plaintext attack in which a large number of plaintext-ciphertext pairs are used to determine the value of key bits. Linear cryptanalysis works on the principle of finding “high probability occurrences of linear expressions involving plaintext bits, ciphertext bits, and subkey bits". Furthermore, we show that DESL is more resistant against the linear cryptanalysis attack than classical DES.