Signcryption ensures encryption and signature with minimum computational costs and overheads than compared to that of traditional signature model. Besides, Certificateless Signcryption resolves issues related to key escrow and reduces public key management for Wireless Sensor Network (WSN) setting. There has been some Certificateless Signcryption mechanisms proposed, most of which are proved secured using bilinear pairing operations. However, with pairing being computationally hard to understand and with involvement of heavy group operation minimizes the advantages gained from smaller key size. To address this issue, a scheme called, Quadratic Poly Certificateless Inductive Signcryption (QPCIS) for network security in WSN is presented without using bilinear pairing. The QPCIS scheme inherits the security of quadratic polynomial that possesses lower computation complexity than bilinear pairing. In QPCIS scheme, only designated receiver node recovers the data packet via base station by verifying validity of signcrypted data packet using Inductive Probability theorem. Experimental works are conducted on parameters like computational time, computational overhead, data security and data integrity rate. By evaluating the performance with related schemes, results show that the proposed QPCIS scheme is secure and computationally efficient.