To evaluate an ultra-lightweight blockcipher Piccolo’s ability to counteract Power Analysis Attack (PAA), an attack model, which focuses on the first round of Piccolo, was proposed and Correlation Power Analysis (CPA) was conducted on this cipher based on a power simulation acquisition platform. Due to the whiten keys and round permutation for the first round of Piccolo, attacking keys including RK0L, RK0R, WK₀ and WK₁ were divided into six sub-keys, which were disclosed one by one. This approach can reduce the 80-bit primary key search space from 2⁸⁰ to (2×2²⁰+2×2⁴+2×2⁸+2¹⁶) and make it possible to recover the primary key. The attack results show that 500 power traces are enough to recover Piccolo’s 80-bit primary key. It is concluded that the hardware implementation of Piccolo without any countermeasure is vulnerable to CPA and some countermeasures should be used. This work is the first known report about the security of Piccolo against PAA.